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1

Design and evaluation of the RF anechoic chamber at HSD  

Microsoft Academic Search

Work carried out during various stages of design, construction, and evaluation of RF screened, anechoic 18.3 x 7.3 x 7.3 m rectangular chamber at HSD Stevenage is described. Results are presented of the reflectivity for the 3 cu m and 3 x 2.5 x 2.5 m volumes of the quiet zone. The design of this RF anechoic facility followed four

D. Draper; Z. F. Voyner

1977-01-01

2

Modeling semi-anechoic electromagnetic measurement chambers  

Microsoft Academic Search

Previous studies developed a model to predict theoretically the low-frequency plane-wave reflection coefficient of an array of pyramid cone absorbers such as those used to line anechoic electromagnetic measurement chambers. The present authors apply this model in a geometrical optics approach to predict the electromagnetic field in a chamber lined with cone absorbers in the frequency range of 30-300 MHz.

Christopher L. Holloway; Edward F. Kuester

1996-01-01

3

Anechoic chambers for EMC, APM and RCS measurements  

Microsoft Academic Search

Summary form only given. This tutorial includes a brief introduction to anechoic chambers and absorber technology. It shows a typical, basic approach to anechoic chamber design for different applications from electromagnetic compatibility (EMC) and radar cross section (RCS) measurements to antenna pattern measurements (APM).

V. Rodriguez

2010-01-01

4

Design and construction of a multipurpose wideband anechoic chamber  

Microsoft Academic Search

An electromagnetic anechoic chamber has been constructed at the Multimedia University. It is designed to operate over a very wide frequency range from 30 MHz through 18 GHz. It can be used for electromagnetic compatibility (EMC) tests, antenna measurements, radar cross section (RCS) measurements, testing RF transceivers, calibration of scatterometers, and other electromagnetic research experiments. The geometry of the chamber

B. K. Chung; H. T. Chuah

2003-01-01

5

Methods for anechoic chamber certification at VHF\\/UHF frequencies  

Microsoft Academic Search

This paper describes joint efforts undertaken by Penn State University Applied Research Laboratory, the National Institute of Standards, and the Microwave Vision Group, which includes ORBIT\\/FR Inc. and Satimo. The purpose of this research was to characterize a selected certification method for the performance of the test zone in a large anechoic chamber. The Applied Research Laboratory's chamber in Warminster,

Russell Soerens; John Aubin; Mark Winebrand; Lars J. Foged; Jeffry J. Miller

2011-01-01

6

The technologies for reducing quiet zone level of anechoic chamber  

Microsoft Academic Search

In designing of anechoic chamber with higher quality, when requirements of quiet zone index are higher, it must use the geometrical theory of diffraction instead of the geometrical optics for accuracy. The utilities of the theory in design have been discussed in this paper. Besides, in analysis of reflectivity versus incident angle of absorbing materials, it's used to use linear

DongAn Song; ChongHua Fang; Qi Zhang; Ding-E Wen; XinYang Shi

2010-01-01

7

Methods for Locating Stray-Signal Sources in Anechoic Chambers  

Microsoft Academic Search

Two complementary numerically efficient frequency-domain methods for locating stray-signal sources in anechoic chambers are investigated and applied in combination to actual measurement data. Both methods use single-frequency near-field data collected on a planar surface and process them to reconstruct field values (images) elsewhere. The first method, which is based on the fact that the probe output satisfies the Helmholtz equation,

Thorkild B. Hansen; Richard A. Marr; Justin S. Hsia; Kristopher T. Kim; Uve H. W. Lammers; Jimmie J. Perez; Timothy J. Tanigawa

2008-01-01

8

Anechoic chamber performance characterization using Spherical Near-Field Imaging techniques  

Microsoft Academic Search

Characterizing the electromagnetic performance of anechoic chambers, particularly large anechoic chambers, can be complex and time consuming. Two measurement techniques commonly used for chamber characterization include free space VSWR and quiet zone probing. The data produced by these chamber evaluation techniques is generally not sufficient to fully characterize the entire chamber. This paper presents a characterization technique utilizing spherical near-field

Carl W. Sirles; John C. Mantovani; A. Ray Howland; Beau J. Hart

2009-01-01

9

New Electronic System for Usrd Anechoic-Tank Facility.  

National Technical Information Service (NTIS)

The transducer calibration system of the Anechoic Tank Facility at USRD has been improved by replacing its original components with electronic equipment of the latest design. A precision frequency synthesizer, a unique synthesizer controller, toneburst an...

C. W. Stoops

1970-01-01

10

Hybrid of periodic dyadic Green's function and FEM for quiet zone analysis in anechoic chamber  

Microsoft Academic Search

Quiet zone is a region in the anechoic chamber where the reflexivity is controlled at a designed level. Analytical formulation and hybrid methods are implemented to analyze the quiet zone in an anechoic chamber, since it is difficult to simulate the whole chamber with periodic absorber arrays. Herein the reflection from a single absorber is operated with FEM while the

Lv Feiyan; Chen Song; Sha Fei

2006-01-01

11

Radar image processing for the AFIT anechoic chamber  

NASA Astrophysics Data System (ADS)

The purpose of this study was to begin development of an Inverse Synthetic Aperature Radar imaging capability for the AFIT anechoic chamber. This began with an evaluation of the capabilities and limitations of the existing radar system and the chamber itself for this application. Then, after deciding on the image processing approach, software had to be written to collect the data necessary for image processing. This constituted the majority of this study, and resulted in a versatile, user-friendly program that automates the process of collecting data for high-resolution radar images. The program checks that the data to be collected will lead to a valid radar cross-section (RCS) image, but will allow data collection for general radar images. Finally, the image processing software was begun. This made use of commercially available software packages called PC-MATLAB and PRO-MATLAB. Further work is needed on the image processing software to generate calibrated images, and to perform focusing.

Sanders, Brian K.

1990-12-01

12

A two dimensional finite difference time domain analysis of the quiet zone fields of an anechoic chamber  

Microsoft Academic Search

Prediction of anechoic chamber performance is a difficult problem. Electromagnetic anechoic chambers exist for a wide range of frequencies but are typically very large when measured in wavelengths. Three dimensional finite difference time domain (FDTD) modeling of anechoic chambers is possible with current computers but at frequencies lower than most chamber design frequencies. However, two dimensional FDTD (2D-FTD) modeling enables

Deirdre A. Ryan; Raymond J. Luebbers; Truong X. Nguyen; Karl S. Kunz; David J. Steich

1992-01-01

13

GTWT (Garfield Thomas Water Tunnel) Flow-through Anechoic Chamber Design.  

National Technical Information Service (NTIS)

Preliminary cost figures are presented to provide estimates of the funding required to complete the flow through anechoic chamber at the Garfield Thomas Water Tunnel. Information necessary to obtain these estimates required major decisions on the philosop...

J. H. Prout

1986-01-01

14

Numerical methodologies for optimizing and predicting the low frequency behavior of anechoic chambers.  

PubMed

This paper presents a description of the use of simplified numerical methodologies for the optimization of the low cut-off frequency of anechoic and hemi-anechoic chambers. The anechoic chamber is modeled as a cavity with proper surface impedance boundary conditions. First, the shape of the wedges is optimized by means of a minimization-based procedure of a finite element model of such elements in a "virtual" impedance tube for a plane wave field. An equivalent surface impedance of the wedges is determined from those data. An analytical procedure is then used to determine the complex reflection coefficient for spherical waves at oblique incidence. Finally, a complex image source approach is used to predict the sound field within the chamber. The methodology is applied to two anechoic chambers and the results are compared in terms of sound decay along fixed directions and surface pressure distributions. PMID:23862806

Bonfiglio, Paolo; Pompoli, Francesco

2013-07-01

15

Anechoic Chamber test of the Electromagnetic Measurement System ground test unit  

NASA Astrophysics Data System (ADS)

The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

Stevenson, L. E.; Scott, L. D.; Oakes, E. T.

1987-04-01

16

CURRENT DISTRIBUTIONS ALONG A RECEIVING THIN DIPOLE INSIDE IDEAL ANECHOIC AND REVERBERATION CHAMBERS  

Microsoft Academic Search

Abstract—This paper studies the correlation of a receiving thin dipole with an arbitrary load in both anechoic chamber,(AC) and reverberation chamber (RC). In both cases, the method of moments is employed to calculate the current distributions along a thin dipole induced by external fields. In AC, a plane wave with a fixed incident angle and polarization is illuminated on the

Weiye Zhong; Zhongxiang Shen; Yeow Kwang Roland Tai; Wee Jin Koh

2008-01-01

17

OPTIMIZATION AN ANECHOIC CHAMBER WITH RAY-TRACING AND GENETIC ALGORITHMS  

Microsoft Academic Search

Anechoic chambers are used for both emission and immunity testing but the ferrite tiles used to line the inside of the chamber are extremely expensive.This paper describes a method of reducing the number of tiles, whilst ensuring a reliable test environment. In this paper, the ray-tracing method for waves propagation is used for evaluation of the reflectivity level of an

Sayed Mohammad Javad Razavi; Mohammad Khalaj-Amirhosseini

2008-01-01

18

OTA measurements of wireless stations in reverberation chamber versus anechoic chamber: from accuracy models to testing of MIMO systems  

Microsoft Academic Search

The paper will describe the fundamental characteristics of different wave propagation environments (such as Rayleigh fading, Rice fading, and polarization balance; coherence bandwidth and time delay spread; and fading speed, coherence time and Doppler spread), and relate these characteristics to the Line-Of-Sight (LOS) emulated by good anechoic chambers, and the rich isotropic multipath environment emulated by good reverberation chambers. The

Per-Simon Kildal

2010-01-01

19

Calculation And Optimization Of Quiet-Zone In RF Anechoic Chamber  

Microsoft Academic Search

This paper introduces the standing wave method to test quiet-zone and geometrical-optics method to calculate quiet-zone, and compare the results of these methods. At last , two ways to optimize the value of quiet-zone are discussed. This paper has great value in design and test of microwave anechoic chamber.

Hao Xiaojun; Liu Ruifeng; Chen Yongguang; He Jianguo

2006-01-01

20

A two dimensional finite difference time domain analysis of the quiet zone fields of an anechoic chamber  

NASA Astrophysics Data System (ADS)

Prediction of anechoic chamber performance is a difficult problem. Electromagnetic anechoic chambers exist for a wide range of frequencies but are typically very large when measured in wavelengths. Three dimensional finite difference time domain (FDTD) modeling of anechoic chambers is possible with current computers but at frequencies lower than most chamber design frequencies. However, two dimensional FDTD (2D-FTD) modeling enables much greater detail at higher frequencies and offers significant insight into compact anechoic chamber design and performance. A major subsystem of an anechoic chamber for which computational electromagnetic analyses exist is the reflector. First, an analysis of the quiet zone fields of a low frequency anechoic chamber produced by a uniform source and a reflector in two dimensions using the FDTD method is presented. The 2D-FDTD results are compared with results from a three dimensional corrected physical optics calculation and show good agreement. Next, a directional source is substituted for the uniform radiator. Finally, a two dimensional anechoic chamber geometry, including absorbing materials, is considered, and the 2D-FDTD results for these geometries appear reasonable.

Ryan, Deirdre A.; Luebbers, Raymond J.; Nguyen, Truong X.; Kunz, Karl S.; Steich, David J.

1992-01-01

21

Wideband numerical modelling and performance optimisation of arbitrarily-shaped anechoic chambers via an unconditionally stable time-domain technique  

Microsoft Academic Search

A 3-D curvilinear alternating-direction implicit finite-difference time-domain (ADI-FDTD) algorithm for the broadband analysis and optimised design of anechoic and semi-anechoic chambers with arbitrary shape is presented in this paper. The unconditionally stable and frequency-dependent method develops a new family of spatial\\/temporal forms which reduce the critical dispersion errors of existing approaches and allow the precise performance evaluation of essential components

Nikolaos V. Kantartzis; Theodoros D. Tsiboukis

2005-01-01

22

Research on anti-interference of electromagnetic radiation of elevator’s door control system in anechoic chamber  

Microsoft Academic Search

The elevator experimental platform and simulated EMI signal system were built to test anti-interference of radiation in anechoic chamber. The destination was to find the frequency ranges and electric field intension which made the elevator lose its functions. The influence of shielding and ground connection would be researched as well. All the malfunctions would be summarized during the whole experiment.

Zhao Borui; Pan Feng; Lei Min; Xie Shuoguo; Song Zhenfei; Shao Kang

2008-01-01

23

LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility  

SciTech Connect

This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

Candy, J V

1999-10-31

24

Calibration and Demonstration of the New Virginia Tech Anechoic Wind Tunnel  

Microsoft Academic Search

A unique new removable anechoic system and new acoustic treatment for the Virginia Tech Stability Wind Tunnel is described. The new system consists of a Kevlar-walled acoustic test section flanked by two anechoic chambers. In its new configuration the facility is closed aerodynamically and open acoustically, allowing far-field acoustic measurements with a flow quality comparable to that of a hard-

Marcel C. Remillieux; Erin D. Crede; Hugo E. Camargo; Ricardo A. Burdisso; William J. Devenport; Matthew Rasnick; Philip Van Seeters; Amanda Chou

25

Realization of 3 m Semi Anechoic Chamber by Using Crossed-Wedge Shaped Hybrid EM Wave Absorber Consisting of Thin Corrugated Dielectric Lossy Sheet  

NASA Astrophysics Data System (ADS)

This letter proposes a new hybrid EM wave absorber with the crossed-wedge shape, which can be applied to 3m semi anechoic chambers. In this study, we designed a new hybrid EM wave absorber with the crossed-wedge shape, which consisted of the inorganic and organic thin corrugated dielectric lossy sheet containing organic conductive fibers. Then the 3m semi anechoic chamber is constructed in the size of 9.0m × 6.0m × 5.7m (L × W × H) using these absorbers, and also the normalized site attenuation (NSA) is measured according to ANSI C63.4 in the frequency range of 30MHz to 1GHz. As a result, the measured NSA is obtained within ±3dB of the theoretical one.

Saito, Toshifumi; Suzuki, Yoshikazu; Kurihara, Hiroshi

26

National Ignition Facility Target Chamber  

SciTech Connect

On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was necessary to achieve the overall schedule. Plans had to be developed for the precise location and alignment of laser beam ports. Upon completion of the fabrication of the aluminum target chamber in a temporary structure the 130 ton sphere was moved from the temporary construction enclosure to its final location in the target building. Prior to the installation of a concrete shield and after completion of the welding of the chamber penetrations vacuum leak checking was performed to insure the vacuum integrity of target chamber. The entire spherical chamber external surface supports a 40 cm thick reinforced concrete shield after installation in the target building. The final task is a total survey of the laser ports and the contour machining of spacer plates so that laser devices attached to these ports meet the alignment criteria.

Wavrik, R W; Cox, J R; Fleming, P J

2000-10-05

27

New acoustic test facility at Georgia Tech  

Microsoft Academic Search

Georgia Tech's Integrated Acoustics Laboratory (IAL) is a state of the art research facility dedicated to the study of acoustics and vibration. The centerpiece of the laboratory is a 24 ft x24 ft x20 ft full anechoic chamber, which has been in operation since 1998. The IAL is currently expanding to include a reverberation room and hemi-anechoic chamber, designed and

Van Biesel; Kenneth Cunefare

2002-01-01

28

Calibration of fully anechoic rooms and correlation with OATS measurements  

Microsoft Academic Search

Fully anechoic rooms may gradually replace open area test sites as the preferred type of testing facility for the measurement of radiated emissions. The fully anechoic room offers several advantages over the open area test site. Immunity to high ambient signal levels, the capability of being located in metropolitan areas close to the customer base, more uniform field over a

R. A. McConnell; C. Vitek

1996-01-01

29

Design and Operation of a Surface Field Measurement Facility.  

National Technical Information Service (NTIS)

The capability to measure surface fields induced upon scattering obstacles by an incident plane wave can be a very powerful diagnostic tool. A surface field measurement facility is comprized of four basic components: an anechoic chamber to provide a free ...

E. F. Knott

1965-01-01

30

Electromagnetic Radiation (EMR) coupling to complex systems : aperture coupling into canonical cavities in reverberant and anechoic environments and model validation.  

SciTech Connect

Mode-stirred chamber and anechoic chamber measurements were made on two sets of canonical test objects (cylindrical and rectangular) with varying numbers of thin slot apertures. The shielding effectiveness was compared to determine the level of correction needed to compensate the mode-stirred data to levels commensurate with anechoic data from the same test object.

Charley, Dawna R.; Higgins, Matthew B.

2007-12-01

31

Target area chamber system design for the National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.

Wavrik, R.; Boyes, J.; Olson, C.; Dempsey, F.; Garcia, R. [Sandia National Labs., Albuquerque, NM (United States); Karpenko, V.; Anderson, A.; Tobin, M.; Latkowski, J. [Lawrence Livermore National Lab., CA (United States)

1994-06-01

32

An Absorbing Boundary Condition Based on Anechoic Absorber For EM Scattering Computation  

Microsoft Academic Search

A novel absorbing boundary condition (ABC), to be used with finite difference and finite element electromagnetic radiation and scattering problems is described. It is based on anechoic chamber absorber foam geometry, with specified complex permittivity and permeability. The advantage of this absorbing boundary is that it prevents reflections from much wider incident angles than currently used lattice termination conditions. Since

C. M. Rappaport; L. J. Bahrmasel

1992-01-01

33

Evaluation of Gas-filled Ionization Chamber Method for Radon Measurement at Two Reference Facilities  

SciTech Connect

For quality assurance, gas-filled ionization chamber method was tested at two reference facilities for radon calibration: EML (USA) and PTB (Germany). Consequently, the radon concentrations estimated by the ionization chamber method were in good agreement with the reference radon concentrations provided by EML as well as PTB.

Ishikawa, Tetsuo; Tokonami, Shinji; Kobayashi, Yosuke; Sorimachi, Atsuyuki; Yatabe, Yoshinori; Miyahara, Nobuyuki [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan)

2008-08-07

34

A large hemi-anechoic enclosure for community-compatible aeroacoustic testing of aircraft propulsion systems  

NASA Astrophysics Data System (ADS)

A large hemi-anechoic (absorptive walls and acoustically hard floor) noise control enclosure has been erected around a complex of test stands at the NASA Lewis Research Center in Cleveland, Ohio. This new state-of-the-art Aeroacoustic Propulsion Laboratory (APL) provides an all-weather, semisecure test environment while limiting noise to acceptable levels in surrounding residential neighborhoods. The 39.6 m (130 ft) diameter geodesic dome structure houses the new Nozzle Aeroacoustic Test Rig (NATR), an ejector-powered M = 0.3 free jet facility for acoustic testing of supersonic aircraft exhaust nozzles and turbomachinery. A multi-axis, force-measuring Powered Lift Facility (PLF) stand for testing of Short Takeoff Vertical Landing (STOVL) vehicles is also located within the dome. The design of the Aeroacoustic Propulsion Laboratory efficiently accomodates the research functions of two separate test rigs, one of which (NATR) requires a specialized environment for taking acoustic measurements. Absorptive fiberglass wedge treatment on the interior surface of the dome provides a hemi-anechoic interior environment for obtaining the accurate acoustic measurements required to meet research program goals. The APL is the first known geodesic dome structure to incorporate transmission-loss properties as well as interior absorption into a free-standing, community-compatible, hemi-anechoic test facility.

Cooper, Beth A.

35

The vacuum chambers for the VUV SASE FEL at the TESLA test facility (TFF FEL) at DESY.  

SciTech Connect

A vacuum chamber for the VW SASE FEL undulatory at the TESLA Test Facility (TTF) was designed, a prototype was built and tested, and seven complete chambers were manufactured. The chambers use the aluminum extrusion technology developed for the insertion device vacuum chambers of the Advanced Photon Source. Each chamber is 4.5 m long with a beam aperture of 9.5 mm and an external thickness of 11.5 mm. Three of the chambers include ports for integral beam position monitors (10 horizontal and vertical pairs) inserted into the chambers, and all of the chambers include grooves for mounting correction coils. Bimetallic flanges (stainless steel to aluminum) are welded to the ends of the chamber for connection to the beamline. Special processing was performed to meet the stringent vacuum and particle-free requirements of the TTF.

Den Hartog, P. K.; Erdmann, M.; Hahn, U.; Pfluger, J.; Ruter, M.; Trakhtenberg, E. M.; Wiemerslage, G.; Xu, S.

1999-04-20

36

Performance of a drift chamber system for the time projection chamber detector facility at PEP - The PEP-4 TPC collaboration  

SciTech Connect

A system of two cylindrical drift chambers has been designed and constructed to trigger the Time Projection Chamber and to assist in tracking and momentum reconstruction. Performance of these chambers has been studied with data collected from cosmic rays and actual e/sup +/e/sup -/ collisions during recent experimental runs.

Aihara, H.; Alston-Garnjost, M.; Badtke, D.H.; Bakken, J.A.; Barbaro-Galtieri, A.; Barnes, A.V.; Barnett, B.A.; Blumenfeld, B.

1983-02-01

37

Evaluation of Radiated Transfer Functions of a Fuselage Model in an Anechoic and in a Reverberating Radio Frequency Environment  

NASA Astrophysics Data System (ADS)

In an anechoic chamber and in a reverberation chamber Radio Frequency (RF) fields are generated to illuminate a fuselage model. The fields coupled into the fuselage model are assessed. This is done by measurement and numerical computer modelling. For the numerical com- puter modelling fundamentally different approaches are applied with entirely independent model generation. The experimental and numerical results for the two different RF Environments are provided and compared. Aim is to characterize both RF environments for a radiated trans- fer function task and compare experimental and different numerical results to each other.

Rasek, G. A.; Loos, S. E.; Neubauer, M.; Junqua, I.; Schröder, A.; Pascual-Gil, E.

2012-05-01

38

New acoustic test facility at Georgia Tech  

NASA Astrophysics Data System (ADS)

Georgia Tech's Integrated Acoustics Laboratory (IAL) is a state of the art research facility dedicated to the study of acoustics and vibration. The centerpiece of the laboratory is a 24 ft x24 ft x20 ft full anechoic chamber, which has been in operation since 1998. The IAL is currently expanding to include a reverberation room and hemi-anechoic chamber, designed and built by Acoustic Systems. These two chambers will be joined by an 8 ft x8 ft transmission loss opening, allowing for a detailed measurement and analysis of complex barriers. Both chambers will accommodate vehicles and similarly large structures. The reverberation room will have adequate volume for standardized absorption measurements. Each chamber will be equipped with dedicated multichannel data acquisition systems and instrumentation for the support of simultaneous research in all areas of the laboratory. The new test chambers are funded by a grant from the Ford Motor Company and are planned to be completed and fully functional by 1 January 2003.

Biesel, Van; Cunefare, Kenneth

2002-11-01

39

A low-frequency anechoic lining for underwater use  

Microsoft Academic Search

A novel low-frequency anechoic lining for use underwater is investigated both theoretically and experimentally. Measurements are made in an impedance tube. The reflection coefficient of any lining material placed at the end of the tube can be found from the real part of the input mobility. The results are compared with theoretical predictions. The experimental results agree qualitatively with the

J. M. Muggleton; R. J. Pinnington

1990-01-01

40

Tri-component phononic crystals for underwater anechoic coatings  

NASA Astrophysics Data System (ADS)

Localized resonance in phononic crystal, composed of three-dimensional arrays of composite units, has been discovered recently. The composite unit is a high-density sphere coated by soft silicon rubber. In this Letter, the absorptive properties induced by the localized resonance are systemically investigated. The mode conversions during the Mie scattering of a single coated lead sphere in unbounded epoxy are analyzed by referring the elements of the scattering matrix. Then the anechoic properties of a slab containing a plane of such composite scatterers are investigated with the multiple-scattering method by accounting the effects of the multiple scattering and the viscous dissipation. The results show that the longitudinal to transverse mode conversion nearby the locally resonant region is an effective way to enhance the anechoic performance of the finite slab of phononic crystal. Then, the influences of the viscoelasticity of the silicon rubber and the coating thickness on the acoustic properties of the finite slab are investigated for anechoic optimization. Finally, we synthetically consider the destructive scattering in the finite slab of phononic crystal and the backing, and design an anechoic slab composed of bi-layer coated spheres. The results show that the most of the incident energy is absorbed at the desired frequency band.

Zhao, Honggang; Liu, Yaozong; Wen, Jihong; Yu, Dianlong; Wen, Xisen

2007-07-01

41

Tests on an 8\\/100 scale model for the definition of the convergent and collector of CEPRA 19 \\/Anechoic open jet wind tunnel  

Microsoft Academic Search

An 8\\/100 scale model of the CEPRA 19 wind tunnel has been built in order to study and define the shape, size, and position of the jet collector in the tunnel's anechoic chamber. The jet collector is common to the 2 m and 3 m test sections, corresponding to free jet lengths of 5.42 D and 3.96 D, respectively. The

P. Rebuffet; A. Guedel

1981-01-01

42

Comparison of Indiana University Cyclotron Facility Faraday cup proton dosimetry with radiochromic films, a calorimeter, and a calibrated ion chamber  

SciTech Connect

The accuracy and utility of the dosimetry system used for radiation effects research with high energy protons at the Indiana University Cyclotron Facility, IUCF, has been confirmed by comparison with an independently calibrated Markus ion chamber, a Schulz water calorimeter and GAFCHROMIC{trademark} films.

Jones, A.Z.; Bloch, C.D.; Hall, E.R.; Hashemian, R.; Klein, S.B.; Przewoski, B. von; Murray, K.M.; Foster, C.C.

1999-12-01

43

Processing of Prosthetic Heart Valve Sounds from Anechoic Tank Measurements  

SciTech Connect

People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

Candy, J V; Meyer, A W

2001-03-20

44

SHIELDING ANALYSIS FOR X-RAY SOURCES GENERATED IN TARGET CHAMBER OF THE NATIONAL IGNITION FACILITY  

SciTech Connect

Prompt doses from x-rays generated as result of laser beam interaction with target material are calculated at different locations inside the National Ignition Facility (NIF). The maximum dose outside a Target Chamber diagnostic port is {approx} 1 rem for a shot utilizing the 192 laser beams and 1.8 MJ of laser energy. The dose during a single bundle shot (8 laser beams) drops to {approx} 40 mrem. Doses calculated outside the Target Bay doors and inside the Switchyards (except for the 17 ft.-6 in. level) range from a fraction of mrem to about 11 mrem for 192 beams, and scales down proportionally with smaller number of beams. At the 17ft.-6 in. level, two diagnostic ports are directly facing two of the Target Bay doors and the maximum doses outside the doors are 51 and 15.5 mrem, respectively. Shielding each of the two Target Bay doors with 1/4 in. Pb reduces the dose by factor of fifty. One or two bundle shots (8 to 16 laser beams) present a small hazard to personnel in the Switchyards.

Khater, H Y; Brereton, S J; Singh, M S

2008-03-27

45

A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber  

SciTech Connect

An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber wall acts as the primary heat exchanger. During removal, gas is pumped through the laser ports by turbo molecular-drag pumps (TM-DP). For the purpose of reducing organic based lubricants and seals, a magnetically levitated TM-DP is being investigated with pump manufacturers. Currently, magnetically levitated turbo molecular pumps are commercially available. The pumps will be exposed to thermal loads and ionizing radiation (tritium, Ar-41, post detonation neutrons). Although the TM-DP's will be subjected to these various radiations, current designs for similar pumping devices have been hardened and have the ability of locating control electronics in remote radiation shielded enclosures4. The radiation hardened TM-DP's will be 5 required to operate with minimal maintenance for periods of up to 18 continuous months. As part of this initial investigation for developing a conceptual engineering strategy for a gas fill solution, commercial suppliers of low pressure gas pumping systems have been contacted and engaged in this evaluation. Current technology in the area of mechanical pumping systems indicates that the development of a robust pumping system to meet the requirements of the FTF gas fill concept is within the limits of COTS equipment3,4.

C.A. Gentile, W.R. Blanchard, T.A. Kozub, M. Aristova, C. McGahan, S. Natta, K. Pagdon, J. Zelenty

2010-01-14

46

Management of unconverted light for the National Ignition Facility target chamber  

SciTech Connect

The NIF target chamber beam dumps must survive high x-ray, laser, ion, and shrapnel exposures without excessive generation of vapors or particulate that will contaminate the final optics debris shields, thereby making the debris shields susceptible to subsequent laser damage. The beam dumps also must be compatible with attaining and maintaining the required target chamber vacuum and must not activate significantly under high neutron fluxes. Finally, they must be developed, fabricated, and maintained for a reasonable cost. The primary challenge for the beam dump is to survive up to 20 J/cm{sup 2} of lpm light and 1 - 2 J/cm{sup 2} of nominally 200 - 350 eV blackbody temperature x rays. Additional threats include target shrapnel, and other contamination issues. Designs which have been evaluated include louvered hot-pressed boron carbide (B{sub 4}C) or stainless steel (SS) panels, in some cases covered with transparent Teflon film, and various combinations of inexpensive low thermal expansion glasses backed by inexpensive absorbing glass. Louvered designs can recondense a significant amount of ablated material that would otherwise escape into the target chamber. Transparent Teflon was evaluated as an alternative way to capture ablated material. The thin Teflon sheet would need to be replaced after each shot since it exhibits both laser damage and considerable x- ray ablation with each shot. Uncontaminated B{sub 4}C, SS, and low thermal expansion glasses have reasonably small x-ray and laser ablation rates, although the glasses begin to fail catastrophically after 100 high fluence shots. Commercially available absorbing glasses require a pre-shield of either Teflon or low thermal expansion glass to prevent serious degradation by the x-ray fluence. Advantages of the hot-pressed B{sub 4}C and SS over glass are their performance against microshrapnel, their relative indifference to contamination, and their ability to be refurbished by aggressive cleaning using CO{sub 2} pellets, glass beads, high pressure water or ultrasonic tanks. In addition the expected replacement rate to avoid catastrophic failure makes the glass option more costly. SS is less expensive, more easily formed into a louver design with high capture efficiency, and otherwise equivalent to B{sub 4}C. Hence, it would be preferred as long as debris shield damage is not substantially greater for SS as compared to damage from an equivalent mass of contamination of B{sub 4}C. If debris shield damage is problematic, the escape of SS could be mitigated by use of a transparent Teflon film. The Teflon film would require increased target chamber pumping and cleaning capability to accommodate the x-ray decomposition products.

Anderson, A. T.; Bletzer, K.; Burnham, A. K.; Dixit, S; Genin, F. Y.; Hibbard, W.; Norton, J.; Scott, J. M.; Whitman, P. K.

1998-07-08

47

Mars and Lunar Vacuum Chamber Testing Facilities and Vacuum Rated Drill Systems  

NASA Astrophysics Data System (ADS)

Martian and Lunar low pressure and vacuum conditions, respectively, greatly affect the performance of the drilling mechanics and drill hardware. For this reason, it is imperative to test planetary sampling and coring drills under these specific environments. Honeybee Robotics acquired an 11ft vacuum chamber that is currently being used to test drills to 1m depth and more. A separate cooling system is used to maintain low temperature of planetary analog formations such as ice, soil, icy-soils, and rocks. The low temperature increases the strength of these formations and in turn reduces drilling efficiency. The chamber also has a numerous feed troughs that can be used to transfer thermal data from thermocouples embedded inside the drilled sample, and the drill bits. The thermal data is useful to determine the temperature the sample reaches during the drilling process. The drill systems include rotary, rotary-percussive, and rotary-sonic. The latter two, in particular, offer superior performance in hard formations due to impacts and/or vibrations that enhance penetration rate. All the drill systems are vacuum rated and hence can be used as test platforms for vacuum testing.

Zacny, K.; Paulsen, G.; Craft, J.; Maksymuk, M.; Santoro, C.; Wilson, J.

2009-12-01

48

Total scattering cross section improvements from electromagnetic reverberation chambers modeling and stochastic formalism  

Microsoft Academic Search

This article is dedicated to deterministic and stochastic improvements for TSCS computations. Firstly, the To- tal Scattering Cross Section (TSCS) measurements are achieved in a numerical Reverberation Chamber (RC) for different targets. From a theoretical point of view, a free-space environment (for instance an anechoic chamber modeled numerically by absorbing boundary conditions) jointly with plane waves stimulations are needed to

Sebastien Lallechere; Ibrahim El Baba; Pierre Bonnet; Francoise Paladian

2011-01-01

49

Design, Build and Validation of a Small-Scale Combustion Chamber Testing Facility.  

National Technical Information Service (NTIS)

This study investigated the design parameters necessary for the construction and use of a testing facility built to test the combustor section of engines. User inputs were acquired by interview and used in the decisions made in arrangement of pieces of ma...

E. Dittman

2006-01-01

50

Design and operational characteristics of the cryopump high-vacuum system for the 25000-liter target chamber of the Helios laser facility  

Microsoft Academic Search

A vacuum system utilizing two 25000 liter\\/second (HâO) helium refrigerator cryopumps and a 1500 liter\\/second turbomolecular pump has been provided for a 25000-liter volume stainless steel chamber as a part of the Helios laser facility. Design goals for the performance of the vacuum system are to produce a chamber pressure of less than 1 x 10⁻⁶ torr after two hours

N. G. Wilson; K. N. Watts

1979-01-01

51

Design and operational characteristics of the cryopump high-vacuum system for the 25000-l target chamber of the Helios Laser Facility  

Microsoft Academic Search

A vacuum system utilizing two 25 000 l\\/s (HâO) two-stage (20 and 70 K) helium refrigerator (cold gas) cryopumps and a 1500 l\\/s turbomolecular pump has been provided for a 25,000: l-volume stainless steel chamber as a part of the Helios Laser Facility. Design goals for the performance of the vacuum system are to produce a chamber pressure of less

N. G. Wilson; K. N. Watts

1980-01-01

52

Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility  

SciTech Connect

Results are presented from the Fifth Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurements conducted in the EML radon exposure and test facility in May 1996. In total, thirty-four government, private and academic facilities participated in the exercise with over 170 passive and electronic devices exposed in the EML test chamber. During the first week of the exercise, passive and continuous measuring devices were exposed (usually in quadruplicate) to about 1,280 Bq m{sup {minus}3} {sup 222}Rn for 1--7 days. Radon progeny measurements were made during the second week of the exercise. The results indicate that all of the tested devices that measure radon gas performed well and fulfill their intended purpose. The grand mean (GM) ratio of the participants` reported values to the EML values, for all four radon device categories, was 0.99 {plus_minus} 0.08. Eighty-five percent of all the radon measuring devices that were exposed in the EML radon test chamber were within {plus_minus}1 standard deviation (SD) of the EML reference values. For the most part, radon progeny measurements were also quite good as compared to the EML values. The GM ratio for the 10 continuous PAEC instruments was 0.90 {plus_minus} 0.12 with 75% of the devices within 1 SD of the EML reference values. Most of the continuous and integrating electronic instruments used for measuring the PAEC underestimated the EML values by about 10--15% probably because the concentration of particles onto which the radon progeny were attached was low (1,200--3,800 particles cm{sup {minus}3}). The equilibrium factor at that particle concentration level was 0.10--0.22.

Scarpitta, S.C.; Tu, K.W.; Fisenne, I.M.; Cavallo, A.; Perry, P.

1996-10-01

53

Archiving Quality Control Tests in the PHENIX Resistive Plate Chamber Assembly Facility  

NASA Astrophysics Data System (ADS)

The PHENIX collaboration at RHIC studies polarized proton-proton collisions to better understand the spin structure of the proton. PHENIX is in the process of upgrading the muon trigger to improve our capabilities of selecting the muons from the decay of W-bosons which are produced more readily at a high transverse momentum than other muon sources. By triggering on single, high transverse momentum muons, new observations on the spin asymmetries of a proton can be obtained. The trigger upgrade will consist of four stations of Resistive Plate Chambers (RPCs), with stations on each side of the interaction region. Each RPC consists of two Bakelite gas gaps, a copper signal plane, an aluminum case, and several layers of mylar and copper. With all of these parts comes the need to archive the manufacturing and quality assurance information along with test results performed on them. This information is kept in a Postgresql Database in the RPC factory and is maintained, modified, and read out through several PHP web pages. A new output page has been produced that will make all of this information much more accessible. This poster will focus on what data is archived, how it is stored, and how it can be easily retrieved and put to use.

Andrews, Keller

2009-10-01

54

CFD Simulation on the J-2X Engine Exhaust in The Center-Body Diffuser and Spray Chamber at the B-2 Facility.  

National Technical Information Service (NTIS)

A computational fluid dynamic (CFD) code is used to simulate the J-2X engine exhaust in the centerbody diffuser and spray chamber at the Spacecraft Propulsion Facility (B-2). The CFD code is named as the space-time conservation element and solution elemen...

R. Buehrle T. Wey X. Y. Wang

2009-01-01

55

Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility  

SciTech Connect

The results from the May 1995 Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurement conducted in the EML radon exposure and test facility are presented. Represented were 13 participants that measure radon with open faced and diffusion barrier activated carbon collectors, 10 with nuclear alpha track detectors, 9 with short-term and long-term electret/ionization chambers, and 13 with active and passive commercial electronic continuous monitors. For radon progeny, there were four participants that came in person to take part in the grab sampling methodology for measuring individual radon progeny and the potential alpha energy concentration (PAEC). There were 11 participants with continuous and integrating commercial electronic instruments that are used for measuring the PAEC. The results indicate that all the tested instruments that measure radon fulfill their intended purpose. All instruments and methods used for grab sampling for radon progeny did very well. However, most of the continuous and integrating electronic instruments used for measuring the PAEC or working level appear to underestimate the potential risk from radon progeny when the concentration of particles onto which the radon progeny are attached is <5,000 cm{sup -3}.

George, A.C.; Knutson, E.O.; Tu, K.W.; Fisenne, I.M.

1995-12-01

56

Flow chamber  

SciTech Connect

A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

Morozov, Victor (Manassas, VA)

2011-01-18

57

Experimental evaluation of the conversion of emission results obtained from a Reverberation Chamber measurement and a SAR measurement  

Microsoft Academic Search

The reverberation chamber (RC) method has many advantages above the semi anechoic room (SAR) method. The RC method is specifically useful to measure emissions at high frequencies (>1 GHz). This is an important property when we consider the trend of increasing operating frequencies of products and wireless applications. Furthermore, the RC method is useful for immunity tests, where we only

Nico van Dijk; Konika Banerjee

2008-01-01

58

Design and operational characteristics of the cryopump high-vacuum system for the 25 000-l target chamber of the Helios Laser Facility  

SciTech Connect

A vacuum system utilizing two 25 000 l/s (H/sub 2/O) two-stage (20 and 70 K) helium refrigerator (cold gas) cryopumps and a 1500 l/s turbomolecular pump has been provided for a 25,000: l-volume stainless steel chamber as a part of the Helios Laser Facility. Design goals for the performance of the vacuum system are to produce a chamber pressure of less than 1.33 x 10/sup -4/ Pa after two hours pumping from atmospheric pressure. Details of the vacuum system configuration, and typical operating conditions are described. Observations made during operation indicate the cryopumps utilized initially produce expected pumping performance followed by variable performance (pumping speed and ultimate pressure) depending upon pumping history. The turbomolecular pump utilized has demonstrated reproducible pump speed and ultimate pressure. Both pumps produce some vibration which can cause interference with critical components in the target chamber; vibration damping/attenuation has been successfully employed for the turbomolecular pump with similar techniques being studied for use with the cryopumps. Reliability of the machines utilized has been excellent with only routine maintenance required in the first year of operation. Considerable instability in ionization gauges (Bayard--Alpert type) has been experienced where the expected gauge sensitivity of 10 per Torr has been observed to vary from 7.5 to >11.

Wilson, N.G.; Watts, K.N.

1980-01-01

59

EMC mobile facility for system level testing of an aircraft  

Microsoft Academic Search

An Integrated EMC Mobile Test Facility (IEMTF) has been designed and developed for system level testing of an aircraft in lieu of dedicated Anechoic Test Facility (ATF). This facility essentially consists of Radiated Emission (RE), Radiated Susceptibility (RS), Bulk Current Injection (BCI), and Ground Plane Interference (GPI) test systems, housed in a mobile shielded shelter. In this paper the system

M. K. Aravind; T. Parthasarathy; P. N. A. P. Rao; D. C. Pande

1999-01-01

60

Time Domain Antenna Measurements in Compact Ranges and Small Anechoic Chambers: Practice and Modelling, Pattern Error Correction and Antenna Diagnostics.  

National Technical Information Service (NTIS)

The research work in this thesis focuses on three main areas (1) the practice and modeling of time domain antenna measurements, (2) pattern error correction and (3) antenna diagnostics. The new measurement approach has been implemented in a compact antenn...

A. J. Marti Canales

2000-01-01

61

Modeling and Simulation of a Bird’s-eye-Type Ferrite Electromagnetic Wave Absorber For an Anechoic Chamber  

NASA Astrophysics Data System (ADS)

The purpose of this study is to design and fabricate an electromagnetic (EM) wave absorber in order to achieve the wide-band characteristic. We proposed and modeled a bird’s-eye-type EM wave absorber using the equivalent material constants method (EMCM), and we evaluated it through simulation using the finite difference time domain (FDTD) method. The numerical simulation showed that a bird’s-eye-type periodic structure has a better wide-band reflection-reducing characteristic than that of the cutting-cone-type EM wave absorber. The validity of the proposed model was confirmed by comparison with a model with experimental results.

Yoon, Hyun Jin; Kim, Dong Il

2004-07-01

62

Exposure chamber  

DOEpatents

An exposure chamber includes an imperforate casing having a fluid inlet at the top and an outlet at the bottom. A single vertical series of imperforate trays is provided. Each tray is spaced on all sides from the chamber walls. Baffles adjacent some of the trays restrict and direct the flow to give partial flow back and forth across the chambers and downward flow past the lowermost pan adjacent a central plane of the chamber.

Moss, Owen R. (Kennewick, WA); Briant, James K. (Pasco, WA)

1983-01-01

63

Transabdominal Ultrasonography of the Small Bowel After Oral Administration of a Non-absorbable Anechoic Solution: Comparison with Barium Enteroclysis  

Microsoft Academic Search

AIM: The aim of this study was to determine if oral administration of a non-absorbable anechoic solution conveys any benefit during abdominal ultrasound (US), with special reference to its accuracy.MATERIALS AND METHODS: Fifty-three adult out-patients scheduled for small bowel barium enema (SBE) were included. The day before SBE all patients underwent abdominal US before and after oral administration of an

Giuseppe Cittadini; Veronica Giasotto; Giacomo Garlaschi; Enzo de Cicco; Alessandra Gallo; Giorgio Cittadini

2001-01-01

64

Exposure chamber  

DOEpatents

A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

Moss, Owen R. (Kennewick, WA)

1980-01-01

65

Anechoic Sphere Phantoms for Estimating 3-D Resolution of Very High Frequency Ultrasound Scanners  

PubMed Central

Two phantoms have been constructed for assessing the performance of high frequency ultrasound imagers. They also allow for periodic quality assurance tests. The phantoms contain eight blocks of tissue-mimicking material where each block contains a spatially random distribution of suitably small anechoic spheres having a small distribution of diameters. The eight mean sphere diameters are distributed from 0.10 to 1.09 mm. The two phantoms differ primarily in terms of the backscatter coefficient of the background material in which the spheres are suspended. The mean scatterer diameter for one phantom is larger than that for the other phantom resulting in a lesser increase in backscatter coefficient for the second phantom; however, the backscatter curves cross at about 35 MHz. Since spheres have no preferred orientation, all three (spatial) dimensions of resolution contribute to sphere detection on an equal basis; thus, the resolution is termed 3-D. Two high frequency scanners are compared. One employs single-element (fixed focus) transducers, and the other employs variable focus linear arrays. The nominal frequency for the single element transducers were 25 and 55 MHz and for the linear array transducers were 20, 30 and 40 MHz. The depth range for detection of spheres of each size is determined corresponding to determination of 3-D resolution as a function of depth. As expected, the single-element transducers are severely limited in useful imaging depth ranges compared with the linear arrays. Note that these phantoms could also be useful for training technicians in using higher frequency scanners.

Madsen, Ernest L.; Frank, Gary R.; McCormick, Matthew M.; Deaner, Meagan E.; Stiles, Timothy A.

2013-01-01

66

IONIZATION CHAMBER  

DOEpatents

This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.

Redman, W.C.; Shonka, F.R.

1958-02-18

67

Alignment of an x-ray imager line of sight in the National Ignition Facility (NIF) target chamber using a Diagnostic Instrument Manipulator (DIM) and Opposed Port Alignment System (OPAS)  

NASA Astrophysics Data System (ADS)

The National Ignition Facility (NIF) fields multiple varieties of x-ray imaging systems used to diagnose the implosion physics of laser-driven fusion targets. The imagers consist of time-resolved x-ray detectors coupled with a snout assembly for spatial and/or spectral imaging. The instrument is mounted onto a cart that extends into the NIF target chamber, placing it in close proximity to the target and aligning with a tight tolerance using the Opposed Port Alignment System (OPAS). The OPAS is a modified, commercial Schmidt-Cassegrain optical telescope mounted at the target chamber port, opposite the Diagnostic Instrument Manipulator (DIM). In this paper, the approach used to characterize and align the x-ray imaging instruments is described. The characterization includes offline measurements of the pinhole assembly and the detector housing. Online, deviations of the DIM, as it is inserted along rails toward the target chamber center, are characterized and related to the OPAS view. An overview of the offline measurement stations is provided along with the process to develop the relationship between the offline alignment scopes and the OPAS as a function of DIM insertion. The combination of these measurements is used to mathematically construct the predicted location of the x-ray imager line of sight in the OPAS image space and determine the desired pinhole location to record data on a fusion experiment. The alignment accuracy of this approach will be discussed, as demonstrated with various x-ray instruments and pinhole configurations.

Shingleton, N.; Kalantar, D.; Wood, R.; McCarville, T.; Klingmann, J.; Manuel, A.

2012-10-01

68

A large hemi-anechoic enclosure for community-compatible aeroacoustic testing of aircraft propulsion systems  

NASA Astrophysics Data System (ADS)

A large hemianechoic (absorptive walls and acoustically hard floor) noise control enclosure was erected around a complex of test stands at the NASA Lewis Research Center in Cleveland, Ohio. This new state-of-the art Aeroacoustic Propulsion Laboratory (APL) provides an all-weather, semi secure test environment while limiting noise to acceptable levels in surrounding residential neighborhoods. The 39.6-m- (130-ft-) diameter geodesic dome houses the new nozzle aeroacoustic test rig (NATR), an ejector-powered Mach 0.3 free jet facility for acoustic testing of supersonic aircraft exhaust nozzles and turbomachinery. A multiaxis, force-measuring, powered lift facility (PLF) stand for testing short takeoff vertical-landing (STOVL) vehicles is also located in the dome. The design of the Aeroacoustic Propulsion Laboratory efficiently accommodates the research functions of two separate test rigs, one of which (NATR) requires a specialized environment for taking acoustic measurements. An absorptive fiberglass wedge treatment on the interior surface of the dome provides a hemianechoic environment for obtaining the accurate acoustic measurements required to meet research program goals. The APL is the first known geodesic dome structure to incorporate transmission-loss properties as well as interior absorption in a free-standing, community-compatible, hemianechoic test facility.

Cooper, Beth A.

1993-04-01

69

Chamber transport  

SciTech Connect

Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

OLSON,CRAIG L.

2000-05-17

70

Multiple anechoic hepatic nodules in a patient with malignant lymphoma: report of a case with an emphasis on B-mode sonograms  

Microsoft Academic Search

We present a case of hepatic malignant lymphoma (ML) in which the hepatic ML nodules were imaged as round anechoic nodules\\u000a with posterior echo enhancement, mimicking hepatic cysts on B-mode ultrasonography (US). However, the boundary echo between\\u000a the nodules and the surrounding hepatic tissue seemed to be less distinct than that of a hepatic cyst. Contrast-enhanced US\\u000a showed the nodules

Yoko Ohyama; Junko Konno; Chioko Yoshida; Naoko Kudoh; Toshiki Sasaki; Takao Hoshino; Hiroyuki Watanabe; Hideaki Ishida; Kayoko Furukawa; Takako Watanabe

2008-01-01

71

D0 central tracking chamber performance studies  

SciTech Connect

The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an R{Phi} tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against {gamma} {yields} e {sup +} e{sup {minus}} events.

Pizzuto, D.

1991-12-01

72

Field test of electret ion chambers for environmental monitoring  

Microsoft Academic Search

A field test of electret ion chambers was performed to evaluate their performance in making environmental exposure measurements at nuclear facilities. The objectives of the study were to determine electret ion chamber measurements. Three electret ion chambers were placed at each of 40 monitoring locations in the vicinity of a commercial nuclear power station during four consecutive quarters. The electret

R. A. Fjeld; P. Kotrappa; K. J. Montague

1994-01-01

73

Liquid Wall Chambers  

Microsoft Academic Search

The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions

2011-01-01

74

Stove with multiple chambers  

Microsoft Academic Search

A stove is described for burning a solid fuel such as wood. The wall means defines a main air inlet, a combustion gas outlet, and four chambers through which gas passes sequentially from the main air inlet to the combustion gas outlet. The chambers comprises a pre-heat plenum chamber into which the main air inlet opens. A main combustion chamber

1987-01-01

75

Combustion chamber construction  

Microsoft Academic Search

A combustion chamber is described for use in gas turbine engines, the chamber comprising: an inlet for receiving air and fuel to be burned; an outlet for expelling products of combustion; high strength structural frame means disposed between the inlet and the outlet for supporting mechanical forces associated with the chamber; liner means cooperating with the frame and defining a

A. P. Sterman; T. G. Wakeman; J. J. Williams

1986-01-01

76

Stove with multiple chambers  

SciTech Connect

A stove is described for burning a solid fuel such as wood. The wall means defines a main air inlet, a combustion gas outlet, and four chambers through which gas passes sequentially from the main air inlet to the combustion gas outlet. The chambers comprises a pre-heat plenum chamber into which the main air inlet opens. A main combustion chamber contains solid fuel to be burned into which gas passes from the pre-heat plenum chamber, a second combustion chamber which is downstream of the main combustion chamber with respect to the flow of gas from the main air inlet to the combustion gas outlet, and a third combustion chamber from which the combustion gas outlet opens. The stove also comprises a plate having a restricted opening for providing communication between the second and third combustion chambers. And a catalytic converter comprises a body of solid material formed with passageways, the body of solid material being fitted in the restricted opening so that gas passes from the second combustion chamber to the third combustion chamber by way of the passageways in the body.

Black, A.

1987-04-21

77

Auxiliary combustion chamber  

SciTech Connect

An auxiliary combustion chamber is described for an internal combustion engine, the chamber comprises: (a) a chamber liner formed of a ceramic material that is an effective thermal insulator, the chamber liner having substantially hemispherical internal and external surfaces; (b) an outer metal member cast around the chamber liner, the outer member including a substantially hemispherical portion contacting the outer surface of the chamber liner and imparting a compressive stress to the chamber liner; the metal member further includes a substantially cylindrical portion contiguous with the open end of the hemispherical portion and extending beyond the chamber liner; the cylindrical portion has an inner surface of a predetermined inside diameter at ambient temperature; and (c) a substantially cup-shaped nozzle portion formed of a heat-resistant ceramic material and having an orifice disposed in the bottom to provide flow communication from a main combustion chamber to the interior of the auxiliary combustion chamber, the nozzle portion includes a substantially cylindrical outer surface having a diameter greater than predetermined inside diameter of cylindrical portion of the metal member; the nozzle portion is shrink-fit within the cylindrical portion of the outer metal member with the cylindrical outer surface of the ceramic nozzle contacting the inner surface of the cylindrical portion of the metal member. The bottom of the nozzle portion is disposed away from the hemispherical portion of the metal member.

Kawamura, M.; Taniguchi, M.

1987-06-30

78

TRU waste characterization chamber gloveboxes.  

SciTech Connect

Argonne National Laboratory-West (ANL-W) is participating in the Department of Energy's (DOE) National Transuranic Waste Program in support of the Waste Isolation Pilot Plant (WIPP). The Laboratory's support currently consists of intrusive characterization of a selected population of drums containing transuranic waste. This characterization is performed in a complex of alpha containment gloveboxes termed the Waste Characterization Gloveboxes. Made up of the Waste Characterization Chamber, Sample Preparation Glovebox, and the Equipment Repair Glovebox, they were designed as a small production characterization facility for support of the Idaho National Engineering and Environmental Laboratory (INEEL). This paper presents salient features of these gloveboxes.

Duncan, D. S.

1998-07-02

79

The Mars Chamber  

NASA Video Gallery

The Mars chamber is a box about the size of a refrigerator that re-creates the temperatures, pressures, and atmosphere of the Martian surface, essentially creating a Mars environment on Earth! Scientists and engineers use this chamber to test experiments on the Sample Analysis at Mars (SAM) instrument suite--a fully-functioning chemistry lab aboard the Curiosity Mars rover.

gsfcvideo

2012-07-17

80

Combustion chamber noise suppressor  

Microsoft Academic Search

A combustion chamber is described for a hot fog generating machine comprising a hollow cylindrical combustion chamber shell having a closure plate at one end and outlet means at the opposite end for directing hot combustion gasses to a fogging nozzle, air inlet means disposed adjacent the outlet means, fuel inlet means and ignition means mounted in the closure plate

1986-01-01

81

16. NBS TOPSIDE CONTROL ROOM, THE NBS HYPERBARIC CHAMBER IS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. NBS TOPSIDE CONTROL ROOM, THE NBS HYPERBARIC CHAMBER IS VERY CLOSE TO THE WATER'S EDGE AND HERE FOR DIVER EMERGENCY SUPPORT. A MEDICAL STAFF IS LOCATED ON THE MARSHALL SPACE FLIGHT CENTER (MSFC) AND SUPPORTS THE NBS PERSONNEL WHEN HYPERBARIC CHAMBER OPERATION IS NECESSARY. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

82

High power microwave testing in a reverberation chamber  

Microsoft Academic Search

This study shows the feasibility of short pulse testing in a Reverberation Chamber (RC). The main objective of this study was to evaluate the use of a Reverberation Chamber as a High Power Microwave test facility. Current high power microwave sources generate very short pulses (less than 100 ns). Such pulses are not long enough to fill a RC completely

Markus Rothenhaeusler

2009-01-01

83

Swirl chamber type combustion chamber for diesel engine  

Microsoft Academic Search

This patent describes a swirl chamber type combustion chamber for a Diesel engine comprising: a piston head in the chamber defining a concavity which guides the stream of combustion gas injected from the swirl chamber into the main combustion chamber at the top dead center of the piston stroke, the concavity being formed in a substantially triangular configuration with an

K. Hataura; M. Nagahama

1989-01-01

84

Multiwire Proportional Chamber Development.  

National Technical Information Service (NTIS)

The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteri...

R. F. Doolittle U. Pollvogt A. J. Eskovitz

1973-01-01

85

Sleeve reaction chamber system  

DOEpatents

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)

2009-08-25

86

Theoretical and numerical studies of plume flows in vacuum chambers  

Microsoft Academic Search

This thesis consists of three parts: a study of facility effects on the background flow in large vacuum chambers; an analytical study of free molecular flows out of exits with different shape representing thruster plumes; and particle simulations of plasma plume flows from a cluster of Hall thrusters. The first part of this thesis discusses the facility effects on large

Chunpei Cai

2005-01-01

87

Internal combustion chamber  

SciTech Connect

In combination with a high-powered reciprocating piston internal combustion engine, an internal combustion cylinder assembly is described comprising: a cylinder head made of weldable material; a cylinder liner for containing and guiding a reciprocating piston of the engine, a coolant jacket adapted to receive a cooling fluid, mounted on and surrounding the cylinder liner, the jacket being attached to the cylinder head and detachably supported by the cylinder liner, and forming a cooling chamber around the cylinder liner; means to supply the cooling fluid to the cooling chamber and to discharge the cooling fluid therefrom.

Schmitz, D.L.

1988-03-08

88

Bubble Chamber Site  

NSDL National Science Digital Library

This substantial site features a large number of photos of bubble chamber (BC) tracks, many with a discussion of the physics. There is a description of how the BC works and also useful tutorial on reading BC pictures. The high quality of the images and the explanations of the events that are shown make this site especially valuable.

2008-06-11

89

Review of straw chambers  

SciTech Connect

This is a review of straw chambers used in the HRS, MAC, Mark III, CLEO, AMY, and TPC e{sup +}e{sup {minus}} experiments. The straws are 6--8 mm in diameter, operate at 1--4 atmospheres and obtain resolutions of 45--100 microns. The designs and constructions are summarized and possible improvements discussed.

Toki, W.H.

1990-03-01

90

Liquid Wall Chambers  

SciTech Connect

The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

Meier, W R

2011-02-24

91

Multi-chamber deposition system  

DOEpatents

A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)

1989-10-17

92

Multi-chamber deposition system  

DOEpatents

A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)

1989-06-27

93

72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR AND CANAL (LOCATION T) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

94

Three chamber negative ion source  

DOEpatents

A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA); Hiskes, John R. (Livermore, CA)

1985-01-01

95

Resistive plate chambers for muon detection at LHC  

Microsoft Academic Search

One resistive plate chamber made of Chinese materials and one Italian resistive plate chamber have been tested in the Gamma\\u000a Irradiation Facility (GIF) at CERN on a high intensity muon beam together with a137Cs source to give a uniform photon background, and simulating conditions close to those expected for an LHC muon detector.\\u000a The results are analyzed. Good space and

Ye Yanlin; Ying Jun; Ban Yong; Liu Hongtao; Cai Jianxin; Zhu Zimei; Ma Jingguo; Chen Tao; Qian Sijin

2002-01-01

96

Using the Nova target chamber for high-yield targets  

SciTech Connect

The existing 2.2-m-radius Nova aluminum target chamber, coated and lined with boron-seeded carbon shields, is proposed for use with 1000-MJ-yield targets in the next laser facility. The laser beam and diagnostic holes in the target chamber are left open and the desired 10/sup -2/ Torr vacuum is maintained both inside and outside the target chamber; a larger target chamber room is the vacuum barrier to the atmosphere. The hole area available is three times that necessary to maintain a maximum fluence below 12 J/cm/sup 2/ on optics placed at a radius of 10 m. Maximum stress in the target chamber wall is 73 MPa, which complies with the intent of the ASME Pressure Vessel Code. However, shock waves passing through the inner carbon shield could cause it to comminute. We propose tests and analyses to ensure that the inner carbon shield survives the environment. 13 refs.

Pitts, J.H.

1987-09-28

97

Vacuum Chamber Design of NSLS-II Storage Ring  

SciTech Connect

National Synchrotron Light Source II (NSLS II) will be a 3-GeV, 792-meter circumference, 3rd generation synchrotron radiation facility, with ultra low emittance and extremely high brightness. the storage ring has 30 Double-Bend-Achromatic (DBA) cells. in each cell, there are five magnets and chamber girders, and one straight section for insertion devices or Radio Frequency (RF) cavities or injection. Most vacuum chambers are made from extruded aluminum with two different cross sections: one fitted in the dipole magnets, and the other surrounded by multipole magnets. They discuss the layout of the DBA cells, the detailed design of the cell's vacuum chambers, the mounting of the Beam-Position-Monitor (BPM) buttons, discrete absorbers, lumped pumps and the distributed Non-Evaporable Getter (NEG) strips, and describe the fabrication and testing of these prototype cell chambers. The account also details the development of the chamber bakeout process, the NEG stri's supports, and the RF shielded bellows.

Doom,L.; Ferreira, M.; Hseuh, H. C.; Lincoln, F.; Longo, C.; Ravindranath, V.; Sharma, S.

2008-06-11

98

Combustion chamber construction  

SciTech Connect

This patent describes a combustion chamber for use in gas turbine engines is provided with a liner formed of a high temperature material. The liner includes a plurality of annular rings of high temperature material mounted by means of flexible mounting arrangement upon a high strength structural frame. As a result of this mounting arrangement, the liner is substantially isolated from structural forces associated with the combustion chamber, while the frame is substantially isolated from thermal stresses associated with the liner. The individual liner rings may be easily removed for repair or replacement without disassembling the frame and associated components. Furthermore, the decoupling of thermal and structural stresses provides longer life and more dependable operation.

Maclin, H.M.

1989-04-03

99

Combustion chamber construction  

SciTech Connect

A combustion chamber for use in gas turbine engines is provided with a liner formed of a high temperature material. The liner includes a plurality of panels of the material mounted by means of a lost motion mounting arrangement upon a high strength structural frame. As a result of this mounting arrangement, the liner is substantially isolated from structural forces associated with the combustion chamber, while the frame is substantially isolated from thermal stresses associated with the liner. For the purpose of supplying cooling air to the liner panels and frame and cooling air is passed into a plenum to cool the radially outward side of the panels. Transfer means are provided for directing the same air from the plenum to the liner inner surfaces in a cooling film. The liner mounting arrangement disclosed herein is particularly useful with difficult-to-weld liner materials (e.g., oxide dispersion strengthened materials), but its advantages commend its use with other materials also.

Maclin, H.M.

1984-11-06

100

CONTINUOUSLY SENSITIVE BUBBLE CHAMBER  

DOEpatents

A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

Good, R.H.

1959-08-18

101

Recommendations for chamber quantification  

Microsoft Academic Search

Abstract Quantification of cardiac chamber size, ventricular mass and function ranks among,the most,clinically important,and most,frequently,requested,tasks of echocardiography. Over the last decades, echocardiographic methods and techniques haveimprovedandexpandeddramatically,duetotheintroductionofhigherfrequency transducers, harmonic imaging, fully digital machines, left-sided contrast agents, and other technological advancements. Furthermore, echocardiography due to its porta- bility and versatility is now used in emergency rooms, operating rooms, and intensive care units.

Roberto M. Lang; Michelle Bierig; Richard B. Devereux; Frank A. Flachskampf; Elyse Foster; Patricia A. Pellikka; Michael H. Picard; Mary J. Roman; James Seward; Jack Shanewise; Scott Solomon; Kirk T. Spencer; John Sutton; William Stewart

2006-01-01

102

Combustion chamber noise suppressor  

SciTech Connect

A combustion chamber is described for a hot fog generating machine comprising a hollow cylindrical combustion chamber shell having a closure plate at one end and outlet means at the opposite end for directing hot combustion gasses to a fogging nozzle, air inlet means disposed adjacent the outlet means, fuel inlet means and ignition means mounted in the closure plate and liner means disposed concentrically within the cylindrical combustion chamber for controlling the flow of air and combustion gasses within the shell. The liner means includes a liner base having a frustroconical configuration with the smaller diameter end thereof disposed in communication with the outlet means and with the larger diameter end thereof disposed in spaced relation to the shell, circumferentially spaced, longitudinally extending fins extending outwardly from the liner base intermediate the liner base and the shell, a cylindrical liner midsection having circumferentially spaced fins extending outwardly therefrom between the midsection and the shell with the fins supporting the midsection on the larger diameter end of the liner base.

Livingston, A.M.

1986-08-19

103

Engine combustion chamber structure  

SciTech Connect

This patent describes a combustion chamber structure comprising an upper wall surface which is shaped like a pent-roof and into which an intake passage opens, a piston having on a head portion thereof a bulged portion conforming to the upper wall surface in shape, a first bowl portion which is formed substantially at the center of the bulged portion and which is substantially semispherical in shape, a pair of second bowl portions which respectively extend on opposite sides of the first bowl portion to the corresponding ends of the bulged portion of the piston along the edge of the bulged portion and are in communication with the first bowl portion, a swirl generating means which is adapted to generate a swirl of intake air in the combustion chamber when the engine load is light, and a spark plug disposed to substantially face the center of the first bowl portion from the upper wall surface; the swirl generating means being adapted to generate the swirl of intake air in a tangential direction in the combustion chamber; and the diameter of the first bowl portion being larger than the width of the second bowl portion.

Tanaka, H.

1988-09-13

104

Deposition Chamber for Epitaxial Growth.  

National Technical Information Service (NTIS)

A chamber for the epitaxial deposition of thin monocrystalline semiconductors has been tested and is described. The chamber for small substrate plates is within and separated from the heating chamber (a hollow graphite cylinder which may also be made of m...

J. Eckstein P. Polivka J. Petrasek

1967-01-01

105

Multi-anode ionization chamber  

DOEpatents

The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

2010-12-28

106

Neutron irradiation test on ATLAS MDT chambers  

NASA Astrophysics Data System (ADS)

The Monitored Drift Tubes (MDT) chambers of the ATLAS muon spectrometer are crucial for the identification of high-momentum final-state muons, which represent very promising and robust signatures of physics at the LHC. They will operate in a high rate and high background environment and therefore their performances should not significantly degrade for the whole ATLAS data taking. The maximum expected total flux, mainly consisting of neutrons and photons in the MeV range, is of the order of 5 kHz/cm2 for the barrel MDTs, while at SLHC, with machine working at higher luminosity, fluxes can be 10 times higher. To test detector robustness, a MDT test chamber was exposed to intensive neutron irradiation at the TAPIRO ENEA-Casaccia Research Center facility.

Branchini, P.; di Luise, S.; Graziani, E.; Mazzotta, C.; Meoni, E.; Morello, G.; Passeri, A.; Petrucci, F.; Policicchio, A.; Salvatore, D.; Schioppa, M.

2007-04-01

107

Effects of Chamber Geometry and Gas Properties on Hydrodynamic Evolution of IFE Chambers  

SciTech Connect

The rep rate of an inertial fusion energy facility depends on the time-dependent response of the chamber environment between target ignitions. The fusion burn following the target ignition releases large quantities of energy into the chamber. This energy should be removed and the environment should be returned to a quiescent state so that the new fusion target can be positioned for the next cycle. Understanding the hydrodynamic transport of this energy through the chamber fill gas is essential because the multidimensional geometry effects become important on the long time scale, as the fluid interacts with the vessel wall containing various beam access ports. This interaction affects several different modes of the chamber species transport, including convection induced by shock waves and secondary flow, molecular diffusion, electron conductivity and radiation. In order to investigate these phenomena, we have developed SPARTAN code as an assembly of algorithms that were the most suitable for an accurate treatment of the computational problem, such as shock wave resolution and tracking, underlying flow physics and complex wall geometry. This study demonstrates that the geometry effects are critical in affecting the flow during the first 50 milliseconds following the target ignition. Thermal diffusion by molecules and free electrons has only a moderate effect in reducing the temperature extrema and is not sufficient to cool down the chamber to the equilibrium with the chamber wall within 100 ms. Radiation of the background plasma was identified as the only transport mechanism that has approached to this goal, making the chamber environment more suitable for inserting the next target.

Dragojlovic, Zoran; Najmabadi, Farrokh [University of California, San Diego (United States)

2005-05-15

108

Stem corrections for ionization chambers.  

PubMed

Ionization chambers often exhibit a stem effect, caused by interactions of radiation with air near the chamber end, or with dielectric in the chamber stem or cable. These interactions contribute to the apparent measured exposure. To determine the stem efffect for several common ionization chamber systems, exposures were measured with TLD capsules placed at the center of 60Co fields of various sizes. These exposure measurements then were repeated with various ionization chamber systems, including two Victoreen R meters (25- and 100-R chambers), a Capintec 192 dosimeter with a Farmer 0.6-cm3 probe, a PTW transit dose probe, and an EG and G IC-18 probe with a Keithley 610-B electrometer. From a comparison of TLD and ionization chamber measurements of the variation in exposure rate with field size, stem corrections for the different systems were determined within 1%. PMID:1196264

Ibbott, G S; Barnes, J E; Hall, G R; Hendee, W R

109

Radiated emission measurements conducted in the AST semi-anechoic chamber dual polarization broadband gigahertz field simulator and their verification with the measurements done on the open area test site  

Microsoft Academic Search

This paper addresses an innovative method of measuring radiated emission, using a dual polarization, broadband gigahertz field (BGF) simulator. Verification of emission measurements conducted in the BGF simulator with the measurements done on an open area test site (OATS) is presented

A. S. Podgorski; J. Baran

1998-01-01

110

National Ignition Facility system design requirements conventional facilities SDR001  

SciTech Connect

This System Design Requirements (SDR) document specifies the functions to be performed and the minimum design requirements for the National Ignition Facility (NIF) site infrastructure and conventional facilities. These consist of the physical site and buildings necessary to house the laser, target chamber, target preparation areas, optics support and ancillary functions.

Hands, J.

1996-04-09

111

Measurement of the (C sub e) Factor for the NACP Ionisation Chamber in Water Relative to the Farmer HPA Values.  

National Technical Information Service (NTIS)

The report describes the measurement of values of the C(sub e) factor for the NACP-designed ionization chamber in water relative to those for the Farmer NE 2571 chamber. The chambers were compared on the NPL linear electron accelerator and Mobaltron facil...

D. T. Burns

1991-01-01

112

Iran Chamber Society  

NSDL National Science Digital Library

In 2001, the Iran Chamber Society was created in order to provide a non-partisan, non-commercial, comprehensive source of information on Iran. The website's "About Us" section states that their aim is to "create a global awareness about Iranian society and eradicate the misunderstandings and misconceptions about Iranian society, and to play an educational role as well." Visitors will find the website divided up into "Art and Culture", "History", "Society" and "Iran's Guide". The "Exhibitions and Conferences" link on the right side of the homepage leads visitors to a number of exhibitions, including the fascinating "Artistic Murals of Tehran's Metro Stations", which offers a dozen pictures of the beautifully handcrafted murals made of pottery, metal, cement and other materials. The "History" section offers pictures and documents, including some disturbing graphic photos from the Iran-Iraq War in 1980-1988 that appear at the end of the Historic Periods and Events section.

113

Mini-chamber, an advanced protection concept for NIF  

SciTech Connect

Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF `mini-chamber,` designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs.

Peterson, P.F.; Scott, J.M. [Univ. of California, Berkeley, CA (United States)

1996-12-31

114

14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM VAPORS TO DEPOSIT TITANIUM COATING ONTO URANIUM PARTS UNDER A VACUUM. (1/11/83) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

115

Overview of the ICF 1000 MJ experiment chamber design  

SciTech Connect

A conceptual design of an experiment chamber for a high gain ICF facility (1000 MJ) is being developed. Performance goals have been established. Several design approaches are being evaluated through computer simulation, engineering analysis, and experimental testing of candidate first wall components. 10 refs., 3 figs.

Slaughter, D.

1988-09-23

116

13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE E. PARTS WERE WELDED UNDER A VACUUM TO PREVENT CORROSION. (11/6/73) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

117

LAYOUT AND SIZING OF ESF ALCOVES AND REFUGE CHAMBERS  

Microsoft Academic Search

The purpose of this analysis is to establish size requirements and approximate locations of Exploratory Studies Facility (ESF) test and operations alcoves, including refuge chambers during construction of the Topopah Spring (TS) loop. Preliminary conceptual layouts for non-deferred test alcoves will be developed to examine construction feasibility based on current test plans and available equipment. The final location and configuration

Romeo S. Jurani John Beesley

1995-01-01

118

OUTDOOR SMOG CHAMBER EXPERIMENTS TO TEST PHOTOCHEMICAL MODELS: PHASE 2  

EPA Science Inventory

The smog chamber facility of the University of North Carolina was used to provide experimental data for developing and testing kinetic mechanisms of photochemical smog formation. In this study, 128 pairs of experiments were performed using NOx and various hydrocarbons and hydroca...

119

ECRB REFUGE CHAMBER  

SciTech Connect

The purpose of this calculation is to identify the initial design requirements for refuge stations, including the client requirements, standards, codes, laws, and regulations, general discipline design criteria, and design basis events and hazards. The scope of this document is for the specific task of designing and constructing refuge stations in the Enhanced Characterization Repository Block (ECRB) subsurface openings as necessary personnel safety enhancements to the current construction, maintenance and testing operations. This document is for the construction at the Exploratory Site Facility (ESF). The criteria is not intended to be incorporated into the proposed repository design and does not support Site Recommendation or License Application efforts. This calculation is prepared in accordance with N-3.12Q as a field support calculation and was prepared using the ''Technical Work Plan for Test Facilities Design FY01 Work Activities'' (TWP) (CRWMS M&O 2000b).

J. W. Keifer

2001-12-03

120

A large high vacuum, high pumping speed space simulation chamber for electric propulsion  

NASA Astrophysics Data System (ADS)

Testing high power electric propulsion devices poses unique requirements on space simulation facilities. Very high pumping speeds are required to maintain high vacuum levels while handling large volumes of exhaust products. These pumping speeds are significantly higher than those available in most existing vacuum facilities. There is also a requirement for relatively large vacuum chamber dimensions to minimize facility wall/thruster plume interactions and to accommodate far field plume diagnostic measurements. A 4.57 m (15 ft) diameter by 19.2 m (63 ft) long vacuum chamber at NASA Lewis Research Center is described. The chamber utilizes oil diffusion pumps in combination with cryopanels to achieve high vacuum pumping speeds at high vacuum levels. The facility is computer controlled for all phases of operation from start-up, through testing, to shutdown. The computer control system increases the utilization of the facility and reduces the manpower requirements needed for facility operations.

Grisnik, Stanley P.; Parkes, James E.

1994-01-01

121

Intercalibration of benthic flux chambers  

Microsoft Academic Search

We have compared 14 different sediment incubation chambers, most of them were used on bottom landers. Measurements of mixing time, pressure gradients at the bottom and Diffusive Boundary Layer thickness (DBL) were used to describe the hydrodynamic properties of the chambers and sediment–water solute fluxes of silicate (34 replicates) and oxygen (23 replicates) during three subsequently repeated incubation experiments on

A. Tengberg; P. O. J. Hall; U. Andersson; B. Lindén; O. Styrenius; G. Boland; F. de Bovee; B. Carlsson; S. Ceradini; A. Devol; G. Duineveld; J.-U. Friemann; R. N. Glud; A. Khripounoff; J. Leather; P. Linke; L. Lund-Hansen; G. Rowe; P. Santschi; P. de Wilde; U. Witte

2005-01-01

122

Gas turbine combustion chamber arrangement  

Microsoft Academic Search

A gas turbine has a combustion chamber of toroidal configuration that includes separation structure dividing the combustion chamber into an annular primary zone and an annular dilution zone. Injection of compressor discharge air into the primary zone sets up a toroidal recirculation pattern of generally circular cross-sectional configuration. Fuel slinger structure at the inner periphery of the primary zone has

A. M. Heitmann; W. L. Brassert; D. N. Chouinard

1977-01-01

123

Chamber Music: Skills and Teamwork.  

ERIC Educational Resources Information Center

|Focuses on the benefits of participating in chamber music ensembles, such as the development of a heightened level of awareness, and considers the role of the music educator/conductor. Provides tools and exercises that teachers can introduce to chamber music players to improve their rehearsals and performances. (CMK)|

Villarrubia, Charles

2000-01-01

124

Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers  

Microsoft Academic Search

The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified

Jennifer H. Batten; Gary W. Stutte; Raymond M. Wheeler

1995-01-01

125

Practical statistical correlation of an RF absorber lined chamber and open area EMI test site  

Microsoft Academic Search

The inadequacy of deterministic methods to correlate measurements from a radio frequency (RF) semianechoic absorber lined chamber and open area test site is discussed. An alternate method for statistically estimating correlation is given, based on a large number of measurements of computing products typically tested at the facilities being correlated. Statistical correlation is shown as a chamber enhancement that increases

Scott Roleson

1991-01-01

126

Muon chambers of Argus detector  

SciTech Connect

This paper describes a new universal ARGUS detector created to study e+e- interactions on the DORIS-II collider. The detector consists of a central drift chamber, time-of-flight counters, and an electromagnetic calorimeter. The detector is enclosed on all sides by three layers of muon counters for registration of muons. The entire system of muon chambers of the ARGUS detector has operated stably from October 1982 until today. The background loads of the muon chambers during an experiment are not great. The average number of signals in the chambers is 0.98 per start-up. The operation of the muon chambers has been constantly monitored according to the counting response of the tubes for cosmic particles, and the quality of the gas has been monitored by comparing the positions of the peaks from Fe 55 radioactive sources in test proportional counters at the inlet and outlet of the gas channel.

Aref'ev, A.V.

1986-09-01

127

40 CFR 792.45 - Test system supply facilities.  

Code of Federal Regulations, 2010 CFR

...b) When appropriate, plant supply facilities shall...maintaining algae and aquatic plants. (2) Facilities...in the protocol, for plant growth, including but not limited...greenhouses, growth chambers, light banks, and...

2009-07-01

128

40 CFR 792.45 - Test system supply facilities.  

Code of Federal Regulations, 2010 CFR

...b) When appropriate, plant supply facilities shall...maintaining algae and aquatic plants. (2) Facilities...in the protocol, for plant growth, including but not limited...greenhouses, growth chambers, light banks, and...

2010-07-01

129

40 CFR 160.45 - Test system supply facilities.  

Code of Federal Regulations, 2010 CFR

... (b) When appropriate, plant supply facilities shall be...maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited...greenhouses, growth chambers, light banks, and fields....

2010-07-01

130

40 CFR 160.45 - Test system supply facilities.  

Code of Federal Regulations, 2010 CFR

... (b) When appropriate, plant supply facilities shall be...maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited...greenhouses, growth chambers, light banks, and fields....

2009-07-01

131

Calculating Contained Firing Facility (CFF) explosive  

Microsoft Academic Search

The University of California awarded LLNL contract No. B345381 for the design of the facility to Parsons Infrastructure Technology, Inc., of Pasadena, California. The Laboratory specified that the firing chamber be able to withstand repeated fxings of 60 Kg of explosive located in the center of the chamber, 4 feet above the floor, and repeated firings of 35 Kg of

Lyle

1998-01-01

132

Test beam analysis of the first CMS drift tube muon chamber  

NASA Astrophysics Data System (ADS)

In October 2001 the first produced CMS Barrel Drift Tube (DT) Muon Chamber was tested at the CERN Gamma Irradiation Facility (GIF) using a muon beam. A Resistive Plate Chamber (RPC) was attached to the top of the DT chamber, and, for the first time, both detectors were operated coupled together. The performance of the DT chamber was studied for several operating conditions, and for gamma rates similar to the ones expected at LHC. In this paper we present the data analysis; the results are considered fully satisfactory. Supported by CICYT.

Albajar, C.; Amapane, N.; Arce, P.; Autermann, C.; Bellato, M.; Benettoni, M.; Benvenuti, A.; Bontenackels, M.; Caballero, J.; Cavallo, F. R.; Cerrada, M.; Cirio, R.; Colino, N.; Conti, E.; de La Cruz, B.; dal Corso, F.; Dallavalle, G. M.; Fernández, C.; de Trocóniz, J. Fernández; Fouz, M. C.; García-Abia, P.; García-Raboso, A.; Gasparini, F.; Gasparini, U.; Giacomelli, P.; Gonella, F.; Gulmini, M.; Hebbeker, T.; Hermann, S.; Hoepfner, K.; Jiménez, I.; Josa, I.; Lacaprara, S.; Marcellini, S.; Mariotti, C.; Maron, G.; Maselli, S.; Meneguzzo, A. T.; Monaco, V.; Montanari, A.; Montanari, C.; Montecassiano, F.; Navarria, F. L.; Odorici, F.; Passaseo, M.; Pegoraro, M.; Peroni, C.; Perrotta, A.; Puerta, J.; Reithler, H.; Romero, A.; Romero, L.; Ronchese, P.; Rossi, A.; Rovelli, T.; Sacchi, R.; Sowa, M.; Staiano, A.; Toniolo, N.; Torassa, E.; Vaniev, V.; Vanini, S.; Ventura, S.; Villanueva, C.; Willmott, C.; Zotto, P.; Zumerle, G.

2004-06-01

133

SKAT Bubble Chamber Film Processing.  

National Technical Information Service (NTIS)

The technique of SKAT bubble chamber photographic image processing is briefly described. On the base of the technique 125000 images were processed in neutrino-seances and 182000 images in antineutrino seances. The analysis of geometric reconstruction of t...

D. S. Baranov L. L. Zakamskij A. A. Ivanilov

1984-01-01

134

Directional muon jet chamber for a muon collider (Groovy Chamber)  

SciTech Connect

A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-{psi} coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas.

Atac, M. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Univ. of California, Los Angeles, CA (United States)

1996-10-01

135

RADIATION ENVIRONMENT OF GROWTH CHAMBERS  

EPA Science Inventory

Radiation measurements with different types of meters in several controlled environment facilities have been compiled to demonstrate the problems associated with insuring uniform radiation levels in separate facilities. Data are provided for a quantum meter, three photometers, a ...

136

63. Interior view, kitchen chamber, north elevation. The kitchen chamber ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

63. Interior view, kitchen chamber, north elevation. The kitchen chamber was completed in the first stages of phase III construction. The paneled wall to the fireplace's right displays a phase III molding profile. The mark between the cabinet doors and on the large lower panel indicates the former position of a partition wall. The chimney-breast paneling bears a phase I profile and might have been moved to the room when the fireplace mass in the hall was reduced. - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

137

Experimental verification of correlation algorithm between FAC and open area test site\\/SAC  

Microsoft Academic Search

The main purpose of Fully Anechoic Chamber (FAC) as an alternative facility for EMC compliance testing is to accurately measure the radiated emission generated from equipment-under-test (EUT). The Open Area Test Site (OATS) is the standard test facility for radiated emission measurement, thus the FAC data have to be correlated to the OATS results. In this paper, it is statistically

Jong-Hwa Kwon; Hyung-Do Choi

2003-01-01

138

Pencil-shaped radiation detection ionization chamber  

Microsoft Academic Search

A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the

Suzuki

1979-01-01

139

Impedances of Laminated Vacuum Chambers  

SciTech Connect

First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

Burov, A.; Lebedev, V.; /Fermilab

2011-06-22

140

The LIFE Dynamic Chamber System  

NASA Astrophysics Data System (ADS)

Dry-wall IFE designs such as LIFE utilize Xe fill gas to protect the target chamber first wall from x-ray heating and ionic debris. A key question is how cool, settled and clean the Xe must be to permit beam propagation and target transport, and how to reach this state at a 10+ Hz shot repetition rate. Xe is at low density in the target chamber, and purified Xe is reinjected at higher density and lower temperature into the larger outer chamber. Maintenance of this density difference due to blast waves generated by implosion of the target capsules is being assessed with HYDRA and 3D VTF, and possible validation experiments are being investigated. Detailed gas response near the wall is being studied using 3D Miranda. A laboratory-scale theta pinch experiment will study cooling and beam propagation in Xe.

Rhodes, Mark; Kane, Jave; Latkowski, Jeffery; Cook, Andrew; Divol, Laurent; Loosmore, Gwendolen; Scott, Howard; Scullard, Christian; Tabak, Max; Wilks, Scott; Moses, Gregory; Heltemes, Thad; Sacks, Ryan; Pantano, Carlos; Kramer, Richard

2011-11-01

141

The CLAS drift chamber system  

SciTech Connect

Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on a toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements.

Mestayer, M.D.; Carman, D.S.; Asavaphibhop, B. [and others

1999-04-01

142

Neutron facility for radiobiological studies  

NASA Astrophysics Data System (ADS)

A neutron facility suitable for radiobiological applications is described. The small chamber can house, either, solid targets or a gas target. Using this facility, absorbed doses ranging up to 7.2 Gy were delivered to Drosophila melanogaster larvae in order to study induced somatic mutation and mitiotic recombination. Some preliminary results concerning these effects, related to a mean neutron energy of 2.15 MeV provided by a d + Be source, are presented.

Policroniades, Rafael; Varela, A.; Guzman, J.; Graaf, U.

1997-02-01

143

Atmosphere contamination following repainting of a human hyperbaric chamber complex.  

PubMed

The Naval Medical Research Institute currently conducts hyperbaric research in a Man-Rated Chamber Complex (MRCC) originally installed in 1977. Significant engineering alterations to the MRCC and rusting of some of its interior sections necessitated repainting, which was completed in 1988. Great care was taken in selecting an appropriate paint (polyamide epoxy) and in ensuring correct application and curing procedures. Only very low levels of hydrocarbons were found in the MRCC atmosphere before initial pressurization after painting and curing. After pressurization, however, significant chemical contamination was found. The primary contaminants were aromatic hydrocarbons: xylenes (which were a major component of both the primer and topcoat paint) and ethyl benzene. The role that pressure played in stimulating off-gassing from the paint is not clear; the off-gassing rate was observed to be similar over a large range in chamber pressures from 1.6 to 31.0 atm abs. Scrubbing the chamber atmosphere with the chemical absorbent Purafil was effective in removing the contaminants. Contamination has been observed to slowly decline with chamber use and is expected to continue to improve with time. However, this contamination experience emphasizes the need for a high precision gas analysis program at any diving facility to ensure the safety of the breathing gas and chamber atmosphere. PMID:2219552

Lillo, R S; Morris, J W; Caldwell, J M; Balk, D M; Flynn, E T

1990-09-01

144

Atmosphere contamination following repainting of a human hyperbaric chamber complex  

SciTech Connect

The Naval Medical Research Institute currently conducts hyperbaric research in a Man-Rated Chamber Complex (MRCC) originally installed in 1977. Significant engineering alterations to the MRCC and rusting of some of its interior sections necessitated repainting, which was completed in 1988. Great care was taken in selecting an appropriate paint (polyamide epoxy) and in ensuring correct application and curing procedures. Only very low levels of hydrocarbons were found in the MRCC atmosphere before initial pressurization after painting and curing. After pressurization, however, significant chemical contamination was found. The primary contaminants were aromatic hydrocarbons: xylenes (which were a major component of both the primer and topcoat paint) and ethyl benzene. The role that pressure played in stimulating off-gassing from the paint is not clear; the off-gassing rate was observed to be similar over a large range in chamber pressures from 1.6 to 31.0 atm abs. Scrubbing the chamber atmosphere with the chemical absorbent Purafil was effective in removing the contaminants. Contamination has been observed to slowly decline with chamber use and is expected to continue to improve with time. However, this contamination experience emphasizes the need for a high precision gas analysis program at any diving facility to ensure the safety of the breathing gas and chamber atmosphere.

Lillo, R.S.; Morris, J.W.; Caldwell, J.M.; Balk, D.M.; Flynn, E.T. (Naval Medical Research Institute, Bethesda, MD (USA))

1990-09-01

145

Blogs are Echo Chambers: Blogs are Echo Chambers  

Microsoft Academic Search

In the last decade, blogs have exploded in number, popularity and scope. However, many commentators and researchers speculate that blogs isolate readers in echo chambers, cutting them off from dissenting opin- ions. Our empirical paper tests this hypothesis. Using a hand-coded sample of over 1,000 comments from 33 of the world's top blogs, we find that agreement out- numbers disagreement

Eric Gilbert; Tony Bergstrom; Karrie Karahalios

2009-01-01

146

Laboratory Course on Drift Chambers  

SciTech Connect

Drift chambers play an important role in particle physics experiments as tracking detectors. We started this laboratory course with a brief review of the theoretical background and then moved on to the the experimental setup which consisted of a single-sided, single-cell drift chamber. We also used a plastic scintillator paddle, standard P-10 gas mixture (90% Ar, 10% CH4) and a collimated 90Sr source. During the laboratory session the students performend measurements of the following quantities: a) drift velocities and their variations as function of the drift field; b) gas gains and c) diffusion of electrons as they drifted in the gas.

Garcia-Ferreira, Ix-B.; Garcia-Herrera, J.; Villasenor, L. [Institute of Physics and Mathematics, University of Michoacan, Bdg. C3-Ciudad Universitaria, Morelia, Michoacan, 58040 (Mexico)

2006-09-25

147

Shock tensiometer for multiwire chambers  

SciTech Connect

This paper describes the operation and circuit of a tensometer based on a new method of determining the frequency of natural oscillations of multiwire chambers filaments by means of shock excitation of oscillations that provide sufficient accuracy under the indicated measurement conditions. The device is suitable for measuring the filament tension of chambers of various designs, is simple to operate, and provides high productivity. The range of tension measurement of 0.5-70 g for gold-plated tungsten filaments 20 microm in diameter and 60 cm long is established with the device.

Zyazyula, F.E.; Korenchenko, S.M.; Smirnov, V.S.

1986-08-01

148

Open-chamber combustion study  

NASA Astrophysics Data System (ADS)

The test program was undertaken to research trade-offs between engine design and operational parameters on open-chamber, premixed spark-ignited gas engines, with a primary focus on combustion effects. This included combustion chamber designs which are conceptually diametrically opposed -- a high squish design typical of diesel engines and a virtually quiescent design. The reader should note that these data are somewhat abstract compared to conventional engines, because the Labeco test engine has exceptionally high friction and the lean-burn data were run unboosted.

Meyers, D. P.; Meyer, R. C.

1994-04-01

149

Test chamber for alpha spectrometry  

DOEpatents

Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

Larsen, Robert P. (Downers Grove, IL)

1977-01-01

150

Chamber Theatre: Staging Defamiliarized Prose.  

ERIC Educational Resources Information Center

The purpose of this paper is to advance the state of chamber-theatre theory by providing a mechanism not only for the staging of works of prose fiction using several narrators but also for those works which have been cast in a temporal sequence inconsistent with the customary perception of time. Venn diagrams are used to represent logical…

McGeever, Charles John

151

MPD Thrust Chamber Flow Dynamics.  

National Technical Information Service (NTIS)

Flow within the thrust chamber of an MPD arcjet is examined experimentally and modeled with a two-dimensional MHD code. Two quasi-steady MPD thrusters are considered under the same input conditions of current (21 kA) and total mass flow rate (0.006 kg/s, ...

1990-01-01

152

Coal gasification combustion chamber structure  

US Patent & Trademark Office Database

A combustion chamber for powdered coal and the like having a refractory lined floor with an exit throat at the bottom. The throat is shaped approximately in accordance with the ratios employed in a contraction cone of a wind tunnel to produce a monotonic increase in flow therethrough in order to avoid any clogging by liquid slag and fly ash.

Barot; Devendra T. (W. Covina, CA)

1986-03-04

153

Sizing the vacuum chambers conservatively  

SciTech Connect

This note will examine many different scenarios, both optimistic and pessimistic, for the performance of the B Factory. The primary reason for this is to establish limits for the emittances in the two rings. This information will be needed to ensure that the vacuum chambers are sized to permit the maximum flexibility. 3 refs., 3 tabs.

Hutton, A.

1990-05-21

154

Simulation of Layered Magma Chambers.  

ERIC Educational Resources Information Center

|The principles of magma addition and liquid layering in magma chambers can be demonstrated by dissolving colored crystals. The concepts of density stratification and apparent lack of mixing of miscible liquids is convincingly illustrated with hydrous solutions at room temperature. The behavior of interstitial liquids in "cumulus" piles can be…

Cawthorn, Richard Grant

1991-01-01

155

The CLAS drift chamber system  

Microsoft Academic Search

Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on the toroidal axis. Within the

M. D. Mestayer; D. S. Carman; B. Asavapibhop; F. J. Barbosa; P. Bonneau; S. B. Christo; G. E. Dodge; T. Dooling; W. S. Duncan; S. A. Dytman; R. Feuerbach; G. P Gilfoyle; V. Gyurjyan; K. H Hicks; R. S Hicks; C. E Hyde-Wright; G. Jacobs; A. Klein; F. J Klein; M. V. Kossov; S. E Kuhn; R. A Magahiz; R. W Major; C. Martin; T. McGuckin; J. McNabb; R. A Miskimen; J. A Mueller; B. B. Niczyporuk; J O'Meara; L. M Qin; B. A Raue; J. Robb; F. Roudot; R. A Schumacher; D. J Tedeschi; R. A Thompson; D. Tilles; W. Tuzel; K. VanSyoc; M. F Vineyard; L. B Weinstein; G. R Wilkin; A. Yegneswaran; J. Yun

2000-01-01

156

Chamber and target technology development for inertial fusion energy  

SciTech Connect

Fusion chambers and high pulse-rate target systems for inertial fusion energy (IFE) must: regenerate chamber conditions suitable for target injection, laser propagation, and ignition at rates of 5 to 10 Hz; extract fusion energy at temperatures high enough for efficient conversion to electricity; breed tritium and fuel targets with minimum tritium inventory; manufacture targets at low cost; inject those targets with sufficient accuracy for high energy gain; assure adequate lifetime of the chamber and beam interface (final optics); minimize radioactive waste levels and annual volumes; and minimize radiation releases under normal operating and accident conditions. The primary goal of the US IFE program over the next four years (Phase I) is to develop the basis for a Proof-of-Performance-level driver and target chamber called the Integrated Research Experiment (IRE). The IRE will explore beam transport and focusing through prototypical chamber environment and will intercept surrogate targets at high pulse rep-rate. The IRE will not have enough driver energy to ignite targets, and it will be a non-nuclear facility. IRE options are being developed for both heavy ion and laser driven IFE. Fig. 1 shows that Phase I is prerequisite to an IRE, and the IRE plus NIF (Phase II) is prerequisite to a high-pulse rate. Engineering Test Facility and DEMO for IFE, leading to an attractive fusion power plant. This report deals with the Phase-I R&D needs for the chamber, driver/chamber interface (i.e., magnets for accelerators and optics for lasers), target fabrication, and target injection; it is meant to be part of a more comprehensive IFE development plan which will include driver technology and target design R&D. Because of limited R&D funds, especially in Phase I, it is not possible to address the critical issues for all possible chamber and target technology options for heavy ion or laser fusion. On the other hand, there is risk in addressing only one approach to each technology option. Therefore, in the following description of these specific feasibility issues, we try to strike a balance between narrowing the range of recommended R&D options to minimize cost, and keeping enough R&D options to minimize risk.

Abdou, M; Besenbruch, G; Duke, J; Forman, L; Goodin, D; Gulec, K; Hoffer, J; Khater, H; Kulcinsky, G; Latkowski, J F; Logan, B G; Margevicious, B; Meier, W R; Moir, R W; Morley, N; Nobile, A; Payne, S; Peterson, P F; Peterson, R; Petzoldt, R; Schultz, K; Steckle, W; Sviatoslavsky, L; Tillack, M; Ying, A

1999-04-07

157

Chamber Clearing First Principles Modeling  

SciTech Connect

LIFE fusion is designed to generate 37.5 MJ of energy per shot, at 13.3 Hz, for a total average fusion power of 500 MW. The energy from each shot is partitioned among neutrons ({approx}78%), x-rays ({approx}12%), and ions ({approx}10%). First wall heating is dominated by x-rays and debris because the neutron mean free path is much longer than the wall thickness. Ion implantation in the first wall also causes damage such as blistering if not prevented. To moderate the peak-pulse heating, the LIFE fusion chamber is filled with a gas (such as xenon) to reduce the peak-pulse heat load. The debris ions and majority of the x-rays stop in the gas, which re-radiates this energy over a longer timescale (allowing time for heat conduction to cool the first wall sufficiently to avoid damage). After a shot, because of the x-ray and ion deposition, the chamber fill gas is hot and turbulent and contains debris ions. The debris needs to be removed. The ions increase the gas density, may cluster or form aerosols, and can interfere with the propagation of the laser beams to the target for the next shot. Moreover, the tritium and high-Z hohlraum debris needs to be recovered for reuse. Additionally, the cryogenic target needs to survive transport through the gas mixture to the chamber center. Hence, it will be necessary to clear the chamber of the hot contaminated gas mixture and refill it with a cool, clean gas between shots. The refilling process may create density gradients that could interfere with beam propagation, so the fluid dynamics must be studied carefully. This paper describes an analytic modeling effort to study the clearing and refilling process for the LIFE fusion chamber. The models used here are derived from first principles and balances of mass and energy, with the intent of providing a first estimate of clearing rates, clearing times, fractional removal of ions, equilibrated chamber temperatures, and equilibrated ion concentrations for the chamber. These can be used to scope the overall problem and provide input to further studies using fluid dynamics and other more sophisticated tools.

Loosmore, G

2009-06-09

158

Theoretical and numerical studies of plume flows in vacuum chambers  

NASA Astrophysics Data System (ADS)

This thesis consists of three parts: a study of facility effects on the background flow in large vacuum chambers; an analytical study of free molecular flows out of exits with different shape representing thruster plumes; and particle simulations of plasma plume flows from a cluster of Hall thrusters. The first part of this thesis discusses the facility effects on large vacuum chambers, which is quite important to the Electric Propulsion (EP) community. Based on the fact that the background flows in large vacuum chambers equipped with cryogenic pumps are free molecular, five models are proposed to study the average background pressure and flow velocity and their relation to several facility effects, such as pump sticking coefficient, pump size, wall and pump temperatures, and chamber sidewall length. The analysis are based on the mass flow rates into and out of the chamber, the fluxes along two directions and various number density relations at various stations such as chamber ends and vacuum pumps. The second part of the thesis develops several sets of analytical solutions to free molecular flows out of exits with different shapes. It is demonstrated that the plasma plume flows expanding into vacuum can be studied analytically as a combination of several free molecular flows, if the electric field and collision effects are omitted. There exists a unique relation of velocity and positions. The last part of the thesis presents several three-dimensional particle simulations of plasma plume flows from a cluster of Hall thrusters. A detailed electron fluid model is used to solve important electron properties such as plasma potential and electron temperature. A finite element solver is developed to solve the equations of the electron properties on unstructured meshes. Several important implementation issues are discussed and one significant finding is that the class of particle-to-node weighting schemes based on areas or volumes on an unstructured mesh is inaccurate. This problem is not obvious if the Boltzmann relation is used to determine the plasma potential: however, if the detailed electron model is used to calculate the plasma potential, especially when ionization effects are included in the simulation, then the class of allocation schemes yields invalid results. The other significant treatment that distinguishes these simulations is that background static particles representing the backpressure are assigned velocities sampled from a distribution that takes into consideration the facilities effects. (Abstract shortened by UMI.)

Cai, Chunpei

159

Uncertainty analysis of the AEDC 7V chamber  

NASA Astrophysics Data System (ADS)

For over 30 years, the Space Systems Test Facility and space chambers at the Arnold Engineering Development Center (AEDC) have been used to perform space sensor characterization, calibration, and mission simulation testing of space-based, interceptor, and airborne sensors. In partnership with the Missile Defense Agency (MDA), capability upgrades are continuously pursued to keep pace with evolving sensor technologies. Upgrades to sensor test facilities require rigorous facility characterization and calibration activities that are part of AEDC's annual activities to comply with Major Range Test Facility Base processes to ensure quality metrology and test data. This paper discusses the ongoing effort to characterize and quantify Aerospace Chamber 7V measurement uncertainties. The 7V Chamber is a state-of-the-art cryogenic/vacuum facility providing calibration and high-fidelity mission simulation for infrared seekers and sensors against a low-infrared background. One of its key features is the high fidelity of the radiometric calibration process. Calibration of the radiometric sources used is traceable to the National Institute of Standards and Technology and provides relative uncertainties on the order of two to three percent, based on measurement data acquired during many test periods. Three types of sources of measurement error and top-level uncertainties have been analyzed; these include radiometric calibration, target position, and spectral output. The approach used and presented is to quantify uncertainties of each component in the optical system and then build uncertainty diagrams and easily updated databases to detail the uncertainty for each optical system. The formalism, equations, and corresponding analyses are provided to help describe how the specific quantities are derived and currently used. This paper presents the uncertainty methodology used and current results.

Crider, Dustin; Lowry, Heard; Nicholson, Randy; Mead, Kimberly

2005-05-01

160

Measurement of ionization chamber absorbed dose k{sub Q} factors in megavoltage photon beams  

SciTech Connect

Purpose: Absorbed dose beam quality conversion factors (k{sub Q} factors) were obtained for 27 different types of ionization chamber. The aim was to obtain objective evidence on the performance of a wide range of chambers currently available, and potentially used for reference dosimetry, and to investigate the accuracy of the k{sub Q} calculation algorithm used in the TG-51 protocol. Methods: Measurements were made using the {sup 60}Co irradiator and Elekta Precise linac facilities at the National Research Council of Canada. The objective was to characterize the chambers over the range of energies applicable to TG-51 and determine whether each chamber met the requirements of a reference-class instrument. Chamber settling, leakage current, ion recombination and polarity, and waterproofing sleeve effects were investigated, and absorbed dose calibration coefficients were obtained for {sup 60}Co and 6, 10, and 25 MV photon beams. Only thimble-type chambers were considered in this investigation and were classified into three groups: (i) Reference chambers (''standard''0.6 cm{sup 3} Farmer-type chambers and their derivatives traditionally used for beam output calibration); (ii) scanning chambers (typically 0.1 cm{sup 3} volume chambers used for beam commissioning with 3-D scanning phantoms); and (iii) microchambers (very small volume ion chambers ({<=}0.01 cm{sup 3}) used for small field dosimetry). Results: As might be expected, 0.6 cm{sup 3} thimble chambers showed the most predictable performance and experimental k{sub Q} factors were obtained with a relative uncertainty of 0.1%. The performance of scanning and microchambers was somewhat variable. Some chambers showed very good behavior but others showed anomalous polarity and recombination corrections that are not fully explained at present. For the well-behaved chambers, agreement between measured and calculated k{sub Q} factors was within 0.4%; for some chambers, differences of more than 1% were seen that may be related to the recombination/polarity results. Use of such chambers could result in significant errors in the determination of reference dose in the clinic. Conclusions: Based on the experimental evidence obtained here, specification for a reference-class ionization chamber could be developed that would minimize the error in using a dosimetry protocol with calculated beam quality conversion factors. The experimental k{sub Q} data obtained here for a wide range of thimble chambers can be used when choosing suitable detectors for reference dosimetry and are intended to be used in the upcoming update/addendum to the AAPM TG-51 dosimetry protocol.

McEwen, Malcolm R. [Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2010-05-15

161

Chamber dynamic research with pulsed power  

SciTech Connect

In Inertial Fusion Energy (IFE), Target Chamber Dynamics (TCD) is an integral part of the target chamber design and performance. TCD includes target output deposition of target x-rays, ions and neutrons in target chamber gases and structures, vaporization and melting of target chamber materials, radiation-hydrodynamics in target chamber vapors and gases, and chamber conditions at the time of target and beam injections. Pulsed power provides a unique environment for IFE-TCD validation experiments in two important ways: they do not require the very clean conditions which lasers need and they currently provide large x-ray and ion energies.

PETERSON,ROBERT R.; OLSON,CRAIG L.; RENK,TIMOTHY J.; ROCHAU,GARY E.; SWEENEY,MARY ANN

2000-05-15

162

Open top experimental chambers for trees  

SciTech Connect

A large, relatively light weight open top experimental chamber was designed, constructed, and tested at the University of California, Riverside. The chamber used the essential basic design principles incorporated into the National Crop Loss Assessment Network chambers. However, because of its unique application for trees, the chamber's structural characteristics are basically of original design. This report describes chamber design, construction, and performance characteristics based on 15 months of operation. The chambers are in use and will continue in operation until the fall of 1986. 5 references, 7 figures, 1 table.

Kats, G.; Olszyk, D.M.; Thompson, C.R.

1985-12-01

163

Ionisation Chambers and Secondary Emission Monitors at the PROSCAN Beam Lines  

SciTech Connect

PROSCAN, the dedicated new medical facility at PSI using proton beams for the treatment of deep seated tumours and eye melanoma, is now in the commissioning phase. Air filled ionisation chambers in several configurations are used as current monitors, profile monitors, halo, position and loss monitors at the PROSCAN beam lines. Similar monitors based on secondary emission are used for profile and current measurements in the regime where saturation deteriorates the accuracy of the ionisation chambers.

Doelling, Rudolf [Paul Scherrer Institut (PSI), CH-5232 Villigen-PSI (Switzerland)

2006-11-20

164

Operation of limited streamer mode production-line chambers with non-flammable gases  

NASA Astrophysics Data System (ADS)

Plateaus for two non-flammable gas mixtures have been studied on a statistically meaningful batch of limited streamer mode production-line chambers. These were produced at the Streamer Chamber Assembly and Research Facility (SCARF) in Houston. Useful plateaus were found on all 35 of the randomly selected chambers for a gas composed of 88% CO2 + 10% isobutane + 2% neon, with plateua width of 470+/-72 V, and a gas composed of 88% CO2 + 10% isobutane + 2% argon, with a plateau width of 543+/-80 V. Chambers operated with a standard gas mixture of 75% isobutane + 25% Ar show much longer plateaus, 943+/-311 V, with the plateau limit set by the individual chamber quality, whereas plateaus using the non-flammable gases are found to be gas limited.

Hungerford, Dale; Lau, Kwong; Liu, Jianxiong; Mo, Guang-Hui; Parks, Drew; Pyrlik, Jörg; Sanders, David; Weinstein, Roy; Pei-Ruo, Shen; Xiu-Zhen, Yu

1990-01-01

165

Single wire drift chamber design  

SciTech Connect

This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

Krider, J.

1987-03-30

166

Characterizing the acoustic properties of the Jet Lab at the National Center for Physical Acoustics  

NASA Astrophysics Data System (ADS)

Aerodynamic noise has been a problem since the first use of the jet engine for military aircraft in World War II. For further uses of the jet engine to be possible, problems due to jet noise must be researched and addressed. Anechoic chambers were proposed as a testing facility for research in aerodynamic noise because of their supposed free-field characteristics. The international standard ISO 3745-1977 was introduced to determine whether the facilities could be considered anechoic, semi-anechoic, or neither. An experiment was designed to determine at what frequencies the National Center for Physical Acoustics' Jet Lab Facility is non-anechoic, semi-anechoic, or anechoic. To comply with the guidelines of ISO 3745- 1977, three sources were designed and tested at frequencies from 25 Hz to 16000 Hz. The voltages were acquired at each frequency to calculate the sound pressure level and determine if the calculated values are within the allowed tolerance of the inverse square law.

Lieblong, Joshua Anderson

167

The crop growth research chamber  

NASA Astrophysics Data System (ADS)

The Crop Growth Research Chamber (CGRC) has been defined by CELSS principle investigators and science advisory panels as a necessary ground-based tool in the development of a regenerative life support system. The focus of CGRC research will be on the biomass production component of the CELSS system. The ground-based Crop Growth Research Chamber is for the study of plant growth and development under stringently controlled environments isolated from the external environment. The chamber has importance in three areas of CELSS activities: (1) crop research; (2) system control and integration, and (3) flight hardware design and experimentation. The laboratory size of the CGRC will be small enough to allow duplication of the unit, the conducting of controlled experiments, and replication of experiments, but large enough to provide information representative of larger plant communities. Experiments will focus on plant growth in a wide variety of environments and the effects of those environments on plant production of food, water, oxygen, toxins, and microbes. To study these effects in a closed system, tight control of the environment is necessary.

Wagenbach, Kimberly

168

SMOG CHAMBER VALIDATION USING LAGRANGIAN ATMOSPHERIC DATA  

EPA Science Inventory

A method was developed for validating outdoor smog chamber experiments as a means of determining the relationships between oxidant concentrations and its precursors - hydrocarbons and nitrogen oxides. When chamber experiments were performed in a manner that simulated relevant met...

169

21 CFR 866.2120 - Anaerobic chamber.  

Code of Federal Regulations, 2013 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

2013-04-01

170

Testing of Cover Glasses for Hemacytometer Chambers.  

National Technical Information Service (NTIS)

If cover glasses used with hemacytometer chambers are not sufficiently flat, a volume error, causing erroneous blood cell counts, may be introduced in the chamber. This document describes a method of testing cover glasses for conformity to a planarity spe...

J. S. Beers

1971-01-01

171

Cost Analysis of Portable Refuge Chambers.  

National Technical Information Service (NTIS)

A cost analysis of refuge chambers from an industry perspective was conducted. This analysis quantified costs for the purchase, installation, training, maintenance and inspection, and movement of refuge chambers. Benefits associated with the use of the re...

2008-01-01

172

Development of radon calibration chamber at KRISS  

Microsoft Academic Search

Radon calibration chamber has been constructed to test and calibrate radon and radon progeny detectors at various environmental conditions and to study the characteristic behavior of radon decay products. The size of main room in the chamber is 3.2m×3.3m×2.4m (25.3m3) and the total volume of the chamber is 39.1m3. The maximum concentration of radon in the chamber can be maintained

Jong-Man Lee; Kil Hoon Ahn; Ha Seok Chai; Tae Soon Park

2004-01-01

173

A Sensitive Cloud Chamber without Radioactive Sources  

ERIC Educational Resources Information Center

|We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)|

Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

2012-01-01

174

Making a fish tank cloud chamber  

NASA Astrophysics Data System (ADS)

The cloud chambers described here are large, made from readily available parts, simple to set up and always work. With no source in the chamber, background radiation can be observed. A large chamber means that a long rod containing a weakly radioactive material can be introduced, increasing the chance of seeing decays. Details of equipment and construction are given.

Green, Frances

2012-05-01

175

EPA GAS PHASE CHEMISTRY CHAMBER STUDIES  

EPA Science Inventory

Gas-phase smog chamber experiments are being performed at EPA in order to evaluate a number of current chemical mechanisms for inclusion in EPA regulatory and research models. The smog chambers are 9000 L in volume and constructed of 2-mil teflon film. One of the chambers is co...

176

Plant Exposure Chambers for Dust Studies  

Microsoft Academic Search

Plant exposure chambers are described which provide for uniform application of dusts at rates simulating those of natural conditions. One set of chambers receives artificial light and is used for short term exposures. A second set of larger chambers receives natural light and provides for dusting plants daily to maturity. A feeder assembly from a Bacho Microparticle Classifier serves as

E. F. Darley; S. Lerman; R. J. Oshima

1968-01-01

177

Simple Cloud Chambers Using Gel Ice Packs  

ERIC Educational Resources Information Center

|Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

Kamata, Masahiro; Kubota, Miki

2012-01-01

178

Fluidized wall for protecting fusion chamber walls  

SciTech Connect

Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. Produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithiumceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

Maniscalco, J.A.; Meier, W.R.

1982-08-17

179

Making a Fish Tank Cloud Chamber  

ERIC Educational Resources Information Center

|The cloud chambers described here are large, made from readily available parts, simple to set up and always work. With no source in the chamber, background radiation can be observed. A large chamber means that a long rod containing a weakly radioactive material can be introduced, increasing the chance of seeing decays. Details of equipment and…

Green, Frances

2012-01-01

180

Gas turbine combustion chamber with air scoops  

Microsoft Academic Search

This patent describes a gas turbine combustion chamber. It comprises: means for admission of fuel to the upstream end thereof and discharge of hot gases from the downstream end thereof, and a combustion chamber wall, having an outer surface, with apertures therethrough, and air scoops provided through the apertures to direct air into the combustion chamber.

S. E. Mumford; J. P. Smed

1989-01-01

181

The membrane chamber: A new type of in vitro recording chamber  

Microsoft Academic Search

In vitro brain slice electrophysiology is a powerful and highly successful technique where a thin slice is cut from the brain and kept alive artificially in a recording chamber. The design of this recording chamber is pivotal to the success and the quality of such experiments. Most often one of two types of chambers is used today, the interface chamber

M. R. H. Hill; S. A. Greenfield

2011-01-01

182

THE CIRCUMFUSION SYSTEM FOR MULTIPURPOSE CULTURE CHAMBERS  

PubMed Central

A self-contained mechanical system for circulating nutrient fluid through 12 tissue culture chambers is described in detail. This system utilizes nonperforated cellophane membranes in the chambers which separate the circulating nutrient from the tissue culture environments. The nutrient, therefore, is dialyzed through the cellophane of each chamber; some cell products are retained in the microenvironment between the closely apposed cellophane and cover slip, whereas the other cell products move from chamber to chamber in the circulating nutrient. The resultant environmental conditions directed by the circumfusion systems are highly favorable for maintaining the differentiation of chick embryo tissues over protracted periods; a number of micrographs are shown.

Rose, George G.

1967-01-01

183

Absorption chamber for alkali-helium magnetometer  

SciTech Connect

This paper presents an improved design of an absorption chamber for an alkali-helium magnetometer that ensures reliable firing and maintenance of gas discharge and has a long service life. Use of the improved absorption chamber reduces the HF power of the discharge generator required for firing and maintenance of stable discharge. In addition, owing to introduction into the chamber of an excess amount of alkali metal, whose shielding effect on the discharge is practically eliminated, substantially increases the life of the absorption chamber. Photographs of both the improved and original absorption chambers are provided in the paper.

Blinov, E.V.; Dmitriev, S.P.; Kuleshov, P.P.

1985-12-01

184

New Test Facility for Measuring the Coefficient of Moisture Expansion of Advanced Composite Materials.  

National Technical Information Service (NTIS)

A new test facility designed in order to carefully measure the Coefficient of Moisture Expansion (CME) in specimens made of advanced composite materials is described. The facility is composed essentially of a thermostat contained in a vacuum chamber (10(e...

G. Romeo E. Miraldi G. Ruscica F. Bertoglio G. Ruvinetti

1991-01-01

185

Canister Decontamination Chamber No. 1 operability test results  

SciTech Connect

The DWPF Canister Decontamination Chamber No. 1 (CDC) was installed at the TNX facility in October, 1986 for operability testing. Operability testing was required because this equipment is unique and is a critical part of the defense waste process. The test was successful in demonstrating the canister decontamination operation. Testing verified proper nozzle locations, frit suspension, level probe and CCTV operations. The following recommendations are based on data obtained from frit blasting 24 canisters: reduce the recirculation pump speed, to allow proper level probes operation; add an extension to the chamber rinse nozzle which allows removal of frit from the top of the upper guide rinse nozzle; increase visibility through the CCTV camera; make the CMM grapple jaw pins more compatible with the MSM; and improve canister guide capability to aid in canister loading. CDC Operability Testing was completed October, 1987. 6 refs., 11 figs., 2 tabs.

Magoulas, V.E.

1987-10-30

186

Status of the construction of the Gluex Forward Drift Chambers  

NASA Astrophysics Data System (ADS)

Currently under construction at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia, the full GlueX detector is designed to study gluonic degrees of freedom through the production of ``hybrid'' mesons with exotic quantum numbers. To accomplish this task the detector requires high acceptance and reasonably good resolution for both charged and neutral particles. The core of the detector is housed within the bore of a 2.0 Tesla solenoidal magnet. Charged particles emanating from the target for angles greater than about 20 degrees with respect to the beam line will be tracked with a straw-tube detector (the Central Drift Chamber). Forward-going charged particles will be detected using the Forward Drift Chambers (FDC). I will describe the design and construction of the FDC and present preliminary resolution measurements.

Taylor, Simon

2013-04-01

187

Portable Ethylene Oxide Sterilization Chamber  

PubMed Central

A portable ethylene oxide sterilization chamber was designed, constructed, and tested for use in the sterilization of embolectomy catheters. The unit can accommodate catheters up to 40 inches (101.6 cm) in length and can be operated for less than 4 cents per cycle. A constant concentration of 500 mg of ethylene oxide per liter of space and holding periods of 4 and 6 hr at 43 and 22 C, respectively, were adequate when tested with B. subtilis spores. The estimated cost of construction was $165.00. If temperature control is unnecessary, the cost is approximately $80.00. Images

Songer, J. R.; Mathis, R. G.

1969-01-01

188

The DELPHI time projection chamber  

SciTech Connect

The central tracking device of the DELPHI Experiment at LEP is a Time Projection Chamber (TPC) with an active volume of 2 x 1.34m in length and 2.22m in diameter. Since spring 1988 the TPC has undergone extensive tests in a cosmic ray set-up. It will be installed in the LEP tunnel by early 1989. This report covers the construction, the read-out electronics and the contribution of the TPC to the DELPHI trigger. Emphasis is given to novelties which are not used in similar detectors.

Brand, C.; Cairanti, G.; Charpentier, P.; Clara, M.P.; Delikaris, D.; Foeth, H.; Heck, B.W.; Hilke, H.J.; Sulkowski, K.; Aubret, C.

1989-02-01

189

Radar cross section measurements (8-12 GHz) of flat plates painted with microwave absorbing materials  

Microsoft Academic Search

The aim of the present work is to present radar cross section measurements of flat plates painted with radar absorbing material (RAM) in the range of 8-12 GHz. The measurements were carried out in an anechoic chamber at Centro Tecnico Aeroespacial (CTA)-Ministerio da Defesa facilities, and the RAM coating was manufactured at Divisao de Materiais of Instituto de Aeronautica e

M. C. Rezende; I. M. Martin; M. A. S. Miacci; E. L. Nohara

2001-01-01

190

Application of Impedance Loading to Geometric Transition Radar Absorbent Material  

Microsoft Academic Search

This paper describes a novel, lightweight technique for significantly improving the low-frequency reflectivity performance of conventional geometric transition radar absorbent materials as used typically in anechoic chamber facilities for electromagnetic compatibility testing. The improvement is achieved by the inclusion of impedance-loading elements within the base region of the absorber, and these are implemented in the form of one or more

Kenneth Lee Ford; Barry Chambers

2007-01-01

191

Noise level reduction inside helicopter cabins  

Microsoft Academic Search

A number of measures to reduce the noise level in helicopter cabins are discussed. Laboratory test results of various panellings are presented as well as the insulation capacities of different panel mounts. Experiments in acoustic facilities (anechoic chamber and reverberation room) with the original cabin door and its frame led to an optimization of the transmission losses of door components

Eckehard Laudien; George Niesl

1990-01-01

192

MPD thrust chamber flow dynamics  

NASA Astrophysics Data System (ADS)

Flow within the thrust chamber of a Magnetoplasmadynamic (MPD) arcjet is examined experimentally and modeled with a 2-D magnetohydrodynamic code. Two quasi-steady MPD thrusters are considered under the same input conditions of current (21 kA) and total mass flow rate (0.006 kg/s, argon + 1.5 percent hydrogen). The arcjets have the same basic design, consisting of a central cathode, 3.8 cm diameter and 5 cm long, separated from a coaxial anode of equal length by a uniform gap of 2.3 cm. Two different mass injection arrangements are used (100 percent at mid-radius, and 50 percent at the cathode base, with the remainder at mid-radius). A new spectroscopic analysis procedure is developed that allows distributions of radial speed, heavy particle temperature and turbulent speed to be extracted from chordal measurements of light emission by the two species in the plasma flow. Good qualitative (and reasonable quantitative) agreement exists with distributions calculated by the MHD code, indicating that flow within the thrust chamber expands from an electromagnetically pumped plasma base (vs a pumped jet off the cathode tip). The significant variation of internal flow dynamics with mass injector arrangement implies the need for extensive experimentally validated code modeling in order to evaluate the potential performance of MPD thrusters.

1990-08-01

193

Calculating Contained Firing Facility (CFF) explosive ; firing zone  

Microsoft Academic Search

The University of California awarded LLNL contract No. B345381 for the design of the facility to Parsons Infrastructure & Technology, Inc., of Pasadena, California. The Laboratory specified that the firing chamber be able to withstand repeated fxings of 60 Kg of explosive located in the center of the chamber, 4 feet above the floor, and repeated firings of 35 Kg

Lyle

1998-01-01

194

Rendezvous facilities  

SciTech Connect

The concurrent programming facilities in both Concurrent C and the Ada language are based on the rendezvous concept. Although these facilities are similar, there are substantial differences. Facilities in Concurrent C were designed keeping in perspective the concurrent programming facilities in the Ada language and their limitations. Concurrent C facilities have also been modified as a result of experience with its initial implementations. In this paper, the authors compare the concurrent programming facilities in Concurrent C and Ada, and show that it is easier to write a variety of concurrent programs in Concurrent C than in Ada.

Gehani, N.H.; Roome, W.D.

1988-11-01

195

Neutron-chamber detectors and applications  

SciTech Connect

Detector applications in Nuclear Safeguards and Waste Management have included measuring neutrons from fission and (alpha,n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive; can have large apertures, usually through a thin chamber wall; and offer very good detection efficiency per dollar. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources. 9 refs., 6 figs., 2 tabs.

Fehlau, P.E.; Atwater, H.F.; Coop, K.L.

1990-01-01

196

Ion chamber gamma burst detector  

SciTech Connect

A gamma ray burst detector of x-ray photons 2 to 10 keV is designed to maximize area, 100 m/sup 2/, and sensitivity, 10/sup -10/ ergs cm/sup -2/ s/sup 1/2/ modest directionality, 2 x 10/sup -4/ sr, and minimize thickness, 3 mg cm/sup -2/, as a plastic space balloon ion chamber. If the log N - log S curve for gamma bursts extends as the -3/2 power, the sensitivity is limited by gamma-burst peak overlap in time so that the question of the size spectrum and isotropy is maximally tested. Supernova type I prompt x-ray bursts of congruent to 3-ms duration should be detected at a rate of several per day from supernova at a distance greater than 100 Mpc.

Colgate, S.A.

1981-08-25

197

Internal combustion engine with rotary combustion chamber  

SciTech Connect

This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber, means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means having an air and fuel intake passage, an exhaust gas passage, a rotary valve assembly operatively associated with the head means for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gas from rotary valve assembly and the piston chamber, the head means having a housing with a bore open to the piston chamber accommodating the rotary valve assembly. The valve assembly comprising a cylindrical sleeve located in the bore, the sleeve having an inner surface, an ignition hole, and intake and exhaust ports aligned with the intake passage and exhaust gas passage, spark generating means mounted on the housing operable to generate a spark, rotatable valving means located within the sleeve for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gases out of the rotary valve assembly and piston chamber, the rotatable valving means having a valving combustion chamber open to the piston chamber and the inner surface of the sleeve, the rotatable valving means having a valve body. The valving combustion chamber having an inner portion located in the valve body, the valve body having an outer surface spaced from the inner surface of the sleeve segment seal means mounted on the valve body.

Hansen, C.N.; Cross, P.C.

1988-09-27

198

Drift chamber tracking with neural networks  

SciTech Connect

We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

Lindsey, C.S.; Denby, B.; Haggerty, H.

1992-10-01

199

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

2013-07-01

200

Advanced thrust chambers for miniaturized engines  

NASA Astrophysics Data System (ADS)

The general approach in previous Kinetic Kill Vehicle (KKV) thruster design consisted of separate lightweight and low-cost thrust chambers, injectors and valves. A series of programs including hot-fire testing and hover flight tests has led to the design of a new generation liquid bipropellant thruster with an integrated chamber/injector/valve thruster design. System analyses indicate the composite approach provides thermal management for thrust chambers and that an integral injector/valve contributes to a high thrust to weight ratio thruster. Past experience and development test results of an Advanced Composite material are described. Advanced Composite material selection, chamber fabrication and testing program are discussed. The thrust chambers were evaluated on the basis of oxidation resistance, durability, permeability through the chambers walls, strength and performance with excellent results in all areas. Excellent thrust chamber durability was demonstrated with no measurable erosion after extensive accumulated hot-fire time at high chamber pressure. Results to date indicate that the existing technology provides producible, highly durable chambers for KKV applications.

Pavlinsky, Joseph

1992-07-01

201

Innovative design concepts for the LMF target chamber and related systems  

SciTech Connect

We have examined several design concepts for the Laboratory Microfusion Facility (LMF) target chamber, shielding, and final optics protection. The first is an aluminum chamber using the low- density frost protection proposed by LLNL. It employs helium gas cooling, a vacuum for thermal insulation, and a room-temperature water shield. A composite version of the chamber was also explored, which would have low enough activity to allow access within 24 hours (the aluminum requires 7-12 days cooldown). Two versions show promise: a fairly thin woven fiberglass/epoxy chamber and a thick chopped (or powdered) cast glass/epoxy chamber. Another concept used gas puffing to provide a protective gas layer between the target and the wall. Fast values inject enough gas for wall and optic protection yet keep the target region in high vacuum. This concept can also be used in conjunction with final optics protection. Two versions of this were also explored: one with very fast values that fill the optics tubes just before the shot and one with slower, normally-closed valves that prevent gas in pre-filled optics tubes from entering the chamber until just before the shot. Another optics protection idea proposed is to use a condensible gas in the optics tube and cryopump it before it enters the chamber. A bare wall concept discussed is pyramid arrays, which increase the effective wall surface area. The most promising is cast aluminum array panels. 36 refs., 39 figs., 14 tabs.

Bourgue, R.F.; Cheng, E.T.; Creedon, R.L.; Schultz, K.R.; Sonn, D.L. (General Atomics, San Diego, CA (USA))

1989-06-01

202

OUTDOOR SMOG CHAMBER EXPERIMENTS TO TEST PHOTOCHEMICAL MODELS: MICROFICHE OF DATA COLLECTED IN THE STUDY  

EPA Science Inventory

The smog chamber facility of the University of North Carolina was used in a study to collect experimental data for developing and testing kinetic mechanisms of photochemical smog formation. Listings and plots of the 115 dual all-day experiments conducted in the study are containe...

203

MECHANISMS OF PHOTOCHEMICAL REACTIONS IN URBAN AIR. VOLUME II. CHAMBER STUDIES  

EPA Science Inventory

The smog chamber facility of the Statewide Air Pollution Research Center has been employed in a study designed to provide experimental data required for the validation of kinetic computer models of chemical transformations in polluted atmospheres. A 5800-l, Teflon-coated, evacuab...

204

MEASUREMENT OF GASEOUS EMISSION RATES FROM LAND SURFACES USING AN EMISSION ISOLATION FLUX CHAMBER. USER'S GUIDE  

EPA Science Inventory

A promising method for monitoring ground emissions involves the use of an emission isolation flux chamber. The method is simple, easily available, and inexpensive. Applications would include RCRA and CERCLA facilities. To date, a uniform method operations does not exist. For this...

205

FULL-SCALE CHAMBER INVESTIGATION AND SIMULATION OF AIR FRESHENER EMISSIONS IN THE PRESENCE OF OZONE  

EPA Science Inventory

The paper discusses results of tests, conducted in the EPA large chamber facility, determining emissions and chemical degradation of volatile organic compounds (VOCs) from one electrical plug-in type pine-scented air freshener in the presence of ozone supplied by a device markete...

206

INHALATION TOXICOLOGY OF RED AND VIOLET MIXTURES - CHAMBER CONCENTRATION AND PARTICLE SIZE DISTRIBUTION REPORT  

EPA Science Inventory

An inhalation exposure facility was developed at the U.S. EPA, RTP, NC to conduct inhalation exposures of rodents and guinea pigs to dye mixtures used by the U.S. Army in the manufacture of smoke munitions. nitially, an evaluation of the prototype chamber aerosol homogeneity was ...

207

Development of a Rate of Injection Bench and Constant Volume Combustion Chamber for Diesel Spray Diagnostics  

Microsoft Academic Search

To help understand the complex fuel spray combustion phenomena in modern diesel engine using high injection pressure, a fuel injection test bench and a constant volume combustion chamber were developed and demonstrated in this study for diesel spray diagnostics. Both facilities are significant when linking between spray injection and combustion dynamics and engine performance. This link is important to determine

Anthony Phan

2009-01-01

208

The design and verification of a MEMS combustor chamber  

NASA Astrophysics Data System (ADS)

A pre-combustion micro-mixing chamber has been designed as a component of the University of Arkansas at Little Rock's (UALR) proposed complete microelectromechanical (MEMS) hybrid rocket on a silicon chip. A MEMS pre-combustion mixer allows identification of pressures and flow rates for stochiometric mixing of combustion gases. The pre-combustion mixer has been designed to interface with a mass spectrometer for detection and characterization of combustion reactants and products as the first stage of a UALR hybrid micro-thruster. This research focuses on the design, fabrication, and validation of a pre-combustion micro-mixer that satisfies the requirements of MEMS micro-spacecraft and operates in space conditions. Gases are injected into the chamber via inlet ports and ignited. The combustion products are carried from the device to an online mass spectrometer to verify and quantify the combustion reaction. MEMS design techniques and fabrication facilities are utilized to design a micromixer. The mixing chamber has been qualitatively and quantitatively verified through combustion and mass spectrometry. The detection of water using the mass spectrometer confirmed mixing and combustion, confirming the ability to mix and ignite combustion gases under vacuum conditions. Therefore, for space applications a MEMS combustor may be utilized.

Meadors, Constance Y.

209

A new approach to cooled combustion chambers: The 40K formed platelet chamber  

Microsoft Academic Search

Regeneratively cooled combustion chambers constructed with formed platelet liners have many benefits over chambers with conventionally machined liners. The formed platelet liner offers increased heat transfer efficiency, which can increase cycle life and enhance wall compatibility. A combustion chamber of the 40,000 lb thrust size has been fabricated and tested with a formed platelet liner to demonstrate this superior heat

David E. Janke; William A. Hayes

1992-01-01

210

Formation of soot particulates in the combustion chamber of a precombustion chamber type diesel engine  

Microsoft Academic Search

To clarify the formation processes of soot particulates in the combustion chamber, we sampled the gas during combustion in a precombustion chamber and a main chamber using an electromagnetic sampling valve, and made a gas analysis by gas chromatography, examined the soot concentration, and size distribution and dispersion of soot particulates with a transmission electron microscope. The following results were

Y. Fujiwara; S. Fukazawa; S. Tosaka; T. Murayama

1984-01-01

211

Use of coalescence chambers in separating emulsions  

Microsoft Academic Search

With the aim of obtaining high capacity and satisfactory treating efficiency, various types of apparatus are combined. Chambers with a coalescing charge may be used in such combinations [6]. Since the function of these chambers is not filtration, but rather an enlargement of the disperse-phase drops, they do not have to be regenerated nearly as often as in the case

I. T. Pronin; L. Ya. Esipovich; V. M. Kolin'ko

1985-01-01

212

Active transmitters in a reverberation chamber  

Microsoft Academic Search

This study reports on experiences with EMC testing of strong active transmitters in a reverberation chamber (RC). The main objective of this study was to evaluate the risk of disturbing or even destroying equipment under test in a reverberation chamber. For this reason several equipments with various frequency ranges, from 100 MHz up to 5 GHz, were integrated in an

Markus Rothenhaeusler; Matthias Hahn

2010-01-01

213

Studying Phototropism Using a Small Growth Chamber.  

ERIC Educational Resources Information Center

Describes a simple and inexpensive way to construct two small growth chambers for studying phototropism in the science classroom. One chamber is designed to illustrate how plants grow around obstacles to reach light and the other to illustrate directional light responses. (HM)

Fisher, Maryanna, F.; Llewellyn, Gerald C.

1978-01-01

214

Studying Phototropism Using a Small Growth Chamber.  

ERIC Educational Resources Information Center

|Describes a simple and inexpensive way to construct two small growth chambers for studying phototropism in the science classroom. One chamber is designed to illustrate how plants grow around obstacles to reach light and the other to illustrate directional light responses. (HM)|

Fisher, Maryanna, F.; Llewellyn, Gerald C.

1978-01-01

215

Radon progeny distribution in cylindrical diffusion chambers  

Microsoft Academic Search

An algorithm to model the diffusion of radioactive decay chain atoms is presented. Exact mathematical solutions in cylindrical geometry are given. They are used to obtain expressions for the concentrations of 222Rn progeny atoms in the volume and deposited on the wall surface in cylindrical diffusion chambers. The dependence of volume fractions of 222Rn progeny and chamber sensitivity on the

Dobromir S. Pressyanov

2008-01-01

216

Neutron-chamber detectors and applications  

NASA Astrophysics Data System (ADS)

Detector applications in nuclear safeguards and waste management have included measuring neutrons from fission and (?, n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive, can have large apertures, usually through a thin chamber wall, and offer very good detection efficiency per dollar. For 10% of the cost, a neutron-chamber detector may give one-half the total detection efficiency of a slab detector for detecting neutrons from a distant, bare source. A nuclear-safeguards pedestrian monitor detects concealed plutonium using two such chamber detectors to form a walk-through portal. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources.

Fehlau, Paul E.; Atwater, Henry F.; Coop, Kenneth L.

1990-12-01

217

Controlled-Environment Sunlit Plant Growth Chambers  

Microsoft Academic Search

Controlled environment sunlit plant growth chambers have been built because of a great interest in plant responses to environmental variables under light intensities approaching those of natural sunlight conditions. Individual research projects have designed sunlit chambers that differ in size, structure, material, and environmental control systems dependent on the goals of the projects. Most literature describes plant organism responses to

L. Liu; G. Hoogenboom; K. T. Ingram

2000-01-01

218

Compositional and thermal convection in magma chambers  

Microsoft Academic Search

Magma chambers cool and crystallize at a rate determined by the heat flux from the chamber. The heat is lost predominantly through the roof, whereas crystallization takes place mainly at the floor. Both processes provide destabilizing buoyancy fluxes which drive highly unsteady, chaotic convection in the magma. Even at the lowest cooling rates the thermal Rayleigh number Ra is found

Daniel Martin; Ross W. Griffiths; Ian H. Campbell

1987-01-01

219

Structure of combustion chamber in diesel engine  

Microsoft Academic Search

This patent describes a combustion chamber structure in a diesel engine of a direct injection type having a cylinder block, a cylinder head disposed above the cylinder block, a piston fitted in a cylinder of the cylinder block, a combustion chamber which is formed as a recess in a top part of the piston and whose upper surface is covered

T. Moriyasu; J. Isomoto; T. Nakagami; H. Takahashi; T. Maeda

1988-01-01

220

Pressurized Multiwire Proportional Chamber for Neutron Imaging.  

National Technical Information Service (NTIS)

A pressurizable neutron-sensitive multi-wire proportional chamber has been constructed to test the effect of increased gas density on image resolution. The chamber has dimensions of 25 cm x 25 cm and is pressurizable to 4 atm. With a single-plate converte...

B. Director S. Kaplan V. Perez-Mendez

1977-01-01

221

Test Stand System for Vacuum Chambers.  

National Technical Information Service (NTIS)

A test stand system for supporting test items in a vacuum chamber is described. The system consists of a frame adapted to conform to the inside of the vacuum chamber and supporting a central vertical shaft. The shaft rotates on bearings located at each en...

D. F. Newman

1973-01-01

222

KEK 1 M Hydrogen Bubble Chamber.  

National Technical Information Service (NTIS)

A medium-sized hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition ti...

Y. Doi O. Araoka K. Hayashi Y. Hayashi H. Hirabayashi

1978-01-01

223

Aging in large CDF tracking chambers  

SciTech Connect

The experience of the Collider Detector at Fermilab (CDF) with aging in the large axial drift chamber responsible for tracking in the central region is presented. Premature aging in the Run 1 chamber was observed after only 0.02 C/cm. After cleaning much of the gas system and making modifications to reduce aerosols from the alcohol bubbler, the observed aging rate fell dramatically in test chambers. Considerable effort has been made to better understand the factors that affect aging since the replacement chamber for Run 2 will accumulate about 1.0 C/cm. Current test chambers using the full CDF gas system show aging rates of less than 5%/C/cm.

M. Binkley et al.

2001-03-19

224

RADIATION MONITOR CONTAINING TWO CONCENTRIC IONIZATION CHAMBERS AND MEANS FOR INSULATING THE SEPARATE CHAMBERS  

DOEpatents

This invention relates to a portable radiation monitor containing two concentric ionization chambers which permit the use of standard charging and reading devices. It is particularly adapted as a personnel x-ray dosimeter and to this end comprises a small thin walled, cylindrical conductor forming an inner energy dependent chamber, a small thin walled, cylindrical conductor forming an outer energy independent chamber, and polymeric insulation means which insulates said chambers from each other and holds the chambers together with exposed connections in a simple, trouble-free, and compact assembly substantially without variation in directional response. (AEC)

Braestrup, C.B.; Mooney, R.T.

1964-01-21

225

National Ignition Facility Project: An Update.  

National Technical Information Service (NTIS)

The National Ignition Facility (NIT) consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major cons...

W. J. Hogan E. Moses B. Warner M. Sorem J. Soures J. Hands

2000-01-01

226

Two-chambered right ventricle: simulating two-chambered left ventricle.  

PubMed Central

Two cases are described of a most unusual variant of two-chambered right ventricle. In both the ventricular septal defect was between the distal chamber of the right ventricle and the left ventricle. However the extensive dividing 'septum' between proximal and distal parts of the right ventricle converted the latter, haemodynamically, into part of the left ventricle. In the first case the distal chamber supported the aorta in the left anterior position, the pulmonary artery arising from the proximal part of the right ventricle. In the second the pulmonary artery arose from the distal chamber and the aorta from the proximal chamber. Though in both the ventriculoarterial connection was double outlet right ventricle, functionally there was arterial concordance in case 1 and discordance in case 2. A further disconcerting feature was the resemblance of the distal right ventricular chamber to the rudimentary chamber of a univentricular heart of left ventricular type. Images

Beitzke, A; Anderson, R H; Wilkinson, J L; Shinebourne, E A

1979-01-01

227

Influence of high rotational speeds on heat transfer and oil film thickness in aero-engine bearing chambers  

Microsoft Academic Search

Increasing the thermal loading of bearing chambers in modern aero-engines requires advanced techniques for the determination of heat transfer characteristics. In the present study, film thickness and heat transfer measurements have been carried out for the complex two-phase oil\\/air flow in bearing chambers. In order to ensure real engine conditions, a new test facility has been built up, designed for

S. Wittig; A. Glahn; J. Himmelsbach

1994-01-01

228

The Japanese Radon and Thoron Reference Chambers  

SciTech Connect

Passive detectors used for large-scale and long-term surveys are generally calibrated in a well-controlled environment such as a radon chamber. It has been also pointed out that some of them are sensitive to thoron. Thus it is necessary to check the thoron contribution to the detector response with the proposed or similar test before practical use. The NIRS accommodates radon/aerosol and thoron chambers for quality assurance and quality control of radon measurements. Thus both chambers work so well that they can supply us with the calibration technique and consequently, a good level of knowledge of the radon and thoron issue.

Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Takahashi, Hiroyuki; Miyahara, Nobuyuki [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

2008-08-07

229

Performance of NIRS Thoron Chamber System  

SciTech Connect

In order to carry out thoron sensitivity test for passive radon detectors, a thoron chamber system has been set up at NIRS, Japan. The thoron chamber system consists of four components: the exposure, monitoring, calibration, and humidity control systems, which was mounted in this study due to humidity dependence on the thoron concentration emanated from lantern mantles as the thoron source. The thoron concentration in the thoron chamber is controlled by humidity passed through the thoron source and the weight of the lantern mantle.

Sorimachi, Atsuyuki; Tokonami, Shinji; Takahashi, Hiroyuki; Kobayashi, Yosuke [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

2008-08-07

230

Simple cloud chambers using gel ice packs  

NASA Astrophysics Data System (ADS)

Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry ice or liquid nitrogen. The gel can be frozen in normal domestic freezers, and can be used repeatedly by re-freezing. The tracks of alpha-ray particles can be observed continuously for about 20 min, and the operation is simple and easy.

Kamata, Masahiro; Kubota, Miki

2012-07-01

231

Sample chambers with mother-daughter mode  

SciTech Connect

A set of eight stand-alone sample chambers with a common interface were constructed at LBNL for improved detection of alpha and fission decay chains over currently used designs. The stainless steel chambers (see Figure 1 for a schematic and Figure 2 for a photograph of a completed chamber) were constructed to allow for low background detection of a daughter event by removal of the sample following the detection of a parent event. This mother-daughter mode of operation has been utilized successfully with our Merry-go-Round (MG) detection system [Gregorich 1994].

Wilk, P.A.; Gregorich, K.E.; Hoffman, D.C.

2001-07-12

232

Aerosol Production in IFE Chamber Systems  

SciTech Connect

Preliminary studies have been performed to evaluate the production of aerosols in wetted wall and solid wall IFE chamber configurations. Molten lead and flibe were examined for a wetted-wall chamber 6.5 m in radius, giving aerosol mass concentrations of 20 mg/m{sup 3} and 10 mg/m{sup 3}, respectively, for a simulated 458 MJ indirect-drive target microexplosion. Solid wall materials of tungsten and steel exposed to a 154 MJ direct-drive target microexplosion within an equivalent chamber produced mass concentrations of 0.4 mg/m{sup 3} and 90 mg/m{sup 3}, respectively.

Sharpe, J.P.; Merrill, B.J.; Petti, D.A. [Idaho National Engineering and Environmental Laboratory (United States)

2003-09-15

233

Meeting Today's Requirements for Large Thermal Vacuum Test Facilities.  

National Technical Information Service (NTIS)

The Lockheed Thermal Vacuum Facility at Sunnyvale, California, completed in late 1986, one of the largest multi-program facilities constructed to date is described. The horizontal 12.2 m diameter by 24.4 m long chamber has removable heads at each end and ...

R. L. Corinth J. A. Rouse

1986-01-01

234

Studies of Helium Based Gas Mixtures Using a Small Cell Drift Chamber  

SciTech Connect

An international collaboration is currently working on the construction and design of an asymmetric B Factory at the Stanford Linear Accelerator Center that will be ready to collect data in 1999. The main physics motivation for such a facility is to test the description and mechanism of CP violation in the Standard Model of particle physics and provide insight into the question of why more matter than antimatter is observed in the universe today. In particular, this experiment will measure CP violation in the decay of B mesons. In the early stages of this effort, the Canadian contingent proposed to build the central tracking chamber for the BaBar detector. Presently, a prototype drift chamber is in operation and studies are being performed to test some of the unique features of drift chamber design dictated by the conditions of the experiment. Using cosmic muons, it is possible to study tracking and pattern recognition in the prototype chamber, and therefore calculate the efficiency and spatial resolution of the prototype chamber cells. These performance features will be used to test whether or not the helium-based gas mixtures proposed for the BaBar drift chamber are a viable alternative to the more traditional argon-based gases.

Heise, Jaret; /British Columbia U.

2006-07-07

235

IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities  

SciTech Connect

For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

2005-01-24

236

21 CFR 880.5450 - Patient care reverse isolation chamber.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Patient care reverse isolation chamber. 880.5450 Section 880...880.5450 Patient care reverse isolation chamber. (a) Identification. A patient care reverse isolation chamber is a device...

2013-04-01

237

21 CFR 874.1060 - Acoustic chamber for audiometric testing.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Acoustic chamber for audiometric testing...Diagnostic Devices § 874.1060 Acoustic chamber for audiometric testing. (a) Identification. An acoustic chamber for audiometric...

2013-04-01

238

11. Detail view west from airlock chamber of typical refrigerator ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Detail view west from airlock chamber of typical refrigerator door into Trophic Chamber. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

239

Investigation of the Optical System in the Skat Bubble Chamber.  

National Technical Information Service (NTIS)

In this paper the workout of an algorithm for a bubble chamber ''SKAT'' real photoregistering system's model is given. The problems on possible using of universal geometric programme of bubble chambers for the SKAT chamber are investigated in the assumpti...

V. I. Konyushko V. M. Korablev E. P. Kuznetsov

1975-01-01

240

21 CFR 884.5225 - Abdominal decompression chamber.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Abdominal decompression chamber. 884.5225...Therapeutic Devices § 884.5225 Abdominal decompression chamber. (a) Identification. An abdominal decompression chamber is a...

2010-04-01

241

21 CFR 884.5225 - Abdominal decompression chamber.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Abdominal decompression chamber. 884.5225...Therapeutic Devices § 884.5225 Abdominal decompression chamber. (a) Identification. An abdominal decompression chamber is a...

2009-04-01

242

Structural Analysis of Cylindrical Thrust Chambers, Volume 1.  

National Technical Information Service (NTIS)

Life predictions of regeneratively cooled rocket thrust chambers are normally derived from classical material fatigue principles. The failures observed in experimental thrust chambers do not appear to be due entirely to material fatigue. The chamber coola...

W. H. Armstrong

1979-01-01

243

QUANTIFICATION OF PHOTOSYNTHETICALLY ACTIVE RADIATION INSIDE SUNLIT GROWTH CHAMBERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Naturally sunlit, outdoor growth chambers allow plants to grow under natural light while controlling other environmental variables. Variable transmissions and reflections by chamber walls could attenuate photosynthetically active radiation (PAR) within sunlit chambers from the ambient levels depend...

244

Rapid Evaluation of Mode-Stirred Chambers Using Impulsive Waveforms.  

National Technical Information Service (NTIS)

In this paper, the authors present an experimental technique for the rapid evaluation of mode-stirred (or reverberation) chambers. The measurement provides an estimate of the average chamber quality factor (Q) by measuring the chamber impulse response and...

J. M. Ladbury R. T. Johnk A. R. Ondrejka

1996-01-01

245

30 CFR 57.11054 - Communication with refuge chambers.  

Code of Federal Regulations, 2010 CFR

... false Communication with refuge chambers. 57.11054 Section 57...11054 Communication with refuge chambers. Telephone or other voice...provided between the surface and refuge chambers and such systems shall be...

2009-07-01

246

30 CFR 57.11054 - Communication with refuge chambers.  

Code of Federal Regulations, 2010 CFR

... false Communication with refuge chambers. 57.11054 Section 57...11054 Communication with refuge chambers. Telephone or other voice...provided between the surface and refuge chambers and such systems shall be...

2010-07-01

247

21 CFR 874.1060 - Acoustic chamber for audiometric testing.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Acoustic chamber for audiometric testing...Diagnostic Devices § 874.1060 Acoustic chamber for audiometric testing. (a) Identification. An acoustic chamber for audiometric...

2010-04-01

248

21 CFR 874.1060 - Acoustic chamber for audiometric testing.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Acoustic chamber for audiometric testing...Diagnostic Devices § 874.1060 Acoustic chamber for audiometric testing. (a) Identification. An acoustic chamber for audiometric...

2009-04-01

249

Thrust Chamber Materials and Design Concepts Evaluation.  

National Technical Information Service (NTIS)

A program was conducted to investigate and evaluate new and unique designs of non-regenerative combustion chambers and nozzles using new materials or new techniques for applying the best materials. Analysis of information obtained through literature searc...

D. N. Crump E. G. Parks E. N. Poulos J. B. Pearson K. J. Smith

1967-01-01

250

Ejecting capacity of ejector with mixing chamber  

Microsoft Academic Search

The aim of the studies is to explain the effect of geometrical parameters on the work of ejectors with a short mixing chamber under conditions of isothermality and equal densities in the ejecting and ejected mediums.

V. V. Bondarenko; V. G. Lisienko; B. I. Kitaev

1974-01-01

251

User Manual for LLNL's 24 Chamber Instrument.  

National Technical Information Service (NTIS)

The 24 chamber instrument, called the PolyHanaa, is designed to perform rapid, real-time detection of biological agents using the Polymerase Chain Reaction (PCR) process. Liquid samples are pipetted into small, disposable polypropylene inserts which are p...

J. Richards

2001-01-01

252

HYLIFE-II reactor chamber design refinements  

SciTech Connect

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li{sub 2}BeF{sub 4}) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (>12 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GWe and 2 GWe reactor chamber are presented.

House, P.A.

1994-06-01

253

EFFECT OF DIETHYLHYDROXYLAMINE ON SMOG CHAMBER IRRADIATIONS  

EPA Science Inventory

The addition of diethylhydroxylamine (DEHA) to the urban atmosphere had been suggested as a means of preventing photochemical smog. Smog chamber studies were carried out to investigate the photochemical smog formation characteristics of irradiated hydrocarbon-nitrogen oxides - DE...

254

Ejecting Capacity of Ejector with Mixing Chamber.  

National Technical Information Service (NTIS)

The aim of the studies is to explain the effect of geometrical parameters on the work of ejectors with a short mixing chamber under conditions of isothermality and equal densities in the ejecting and ejected mediums.

B. I. Kitaev V. G. Lisienko V. V. Bondarenko

1974-01-01

255

Large Eddy Simulations of Diesel Combustion Chambers.  

National Technical Information Service (NTIS)

This report presents findings of a systematic study of turbulence predictions for diesel combustion chambers. Particular topics covered include (1) turbulence models for Reynolds averaged Navier-Stokes solutions, (2) turbulence scale analysis, (3) efficie...

I. B. Celik W. S. Lewellen J. M. Kuhlman E. Amin A. Gel

1999-01-01

256

Invention and History of the Bubble Chamber  

ScienceCinema

Don Glaser won the 1960 Nobel Prize for Physics for his 1952 invention of the bubble chamber at Berkeley Lab, a type of particle detector that became the mainstay of high-energy physics research throughout the 1960s and 1970s. He discusses how, inspired by bubbles in a glass of beer, he invented the bubble chamber and detected cosmic-ray muons. His talk was presented July 12, 2006.

257

LCLS EXTRUDED ALUMINUM VACUUM CHAMBER - NEW APPROACHES  

Microsoft Academic Search

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free electron laser when it becomes operational in 2009. Synchrotron radiation will be produced by 33 undulators, each 3.4 meters long, with a fixed gap of 6.8 mm. Vacuum chambers for these undulators should have the maximum possible vertical aperture. Multiple vacuum chambers for insertion devices with 1-mm

Emil Trakhtenberg; Patric DenHartog; Mark Erdmann; Greg Wiemerslage

258

Numerical simulation of magma chamber dynamics.  

NASA Astrophysics Data System (ADS)

Magma chambers are characterized by periodic arrivals of deep magma batches that give origin to complex patterns of magma convection and mixing, and modify the distribution of physical quantities inside the chamber. We simulate the transient, 2D, multi-component homogeneous dynamics in geometrically complex dyke+chamber systems, by means of GALES, a finite element parallel C++ code solving mass, momentum and energy equations for multi-component homogeneous gas-liquid (± crystals) mixtures in compressible-to-incompressible flow conditions. Code validation analysis includes several cases from the classical engineering literature, corresponding to a variety of subsonic to supersonic gas-liquid flow regimes (see http://www.pi.ingv.it/~longo/gales/gales.html). The model allows specification of the composition of the different magmas in the domain, in terms of ten major oxides plus the two volatile species H2O and CO2. Gas-liquid thermodynamics are modeled by using the compositional dependent, non-ideal model in Papale et al. (Chem.. Geol., 2006). Magma properties are defined in terms of local pressure, temperature, and composition including volatiles. Several applications are performed within domains characterized by the presence of one or more magma chambers and one or more dykes, with different geometries and characteristic size from hundreds of m to several km. In most simulations an initial compositional interface is placed at the top of a feeding dyke, or at larger depth, with the deeper magma having a lower density as a consequence of larger volatile content. The numerical results show complex patterns of magma refilling in the chamber, with alternating phases of magma ingression and magma sinking from the chamber into the feeding dyke. Intense mixing takes place in feeding dykes, so that the new magma entering the chamber is always a mixture of the deep and the initially resident magma. Buoyant plume rise occurs through the formation of complex convective patterns, giving origin to a density-stratified magma chamber.

Longo, Antonella; Papale, Paolo; Montagna, Chiara Paola; Vassalli, Melissa; Giudice, Salvatore; Cassioli, Andrea

2010-05-01

259

Advanced technology application for combustion chamber concepts  

Microsoft Academic Search

NASA-Marshall is engaged in the development of an Advanced Main Combustion Chamber under the aegis of the Earth-to-Orbit Propulsion Technology Program. AMCC is to be a robust and highly reliable combustion-chamber prototype costing one-third as much as current designs of comparable performance; it will be associated with a reduction of fabrication time by one-half. Attention is presently given to the

Kathy S. Tygielski

1992-01-01

260

Vapor chamber in high power LEDs  

Microsoft Academic Search

The vapor chamber has already been confirmed that its anti-gravity, high effective thermal conductivity and suited on the high heat flux of heat source as the integral heat spreader. This article describes how to evaluate the thermal-performance of LED vapor chamber-based plate with VCTM V1.0, which has existed in the thermal-module industry for a year or so especially in high

Jung-Chang Wang; Chun-Ling Huang

2010-01-01

261

The drift chambers of the NOMAD experiment  

Microsoft Academic Search

We present a detailed description of the drift chambers used as an active target and a tracking device in the NOMAD experiment at CERN. The main characteristics of these chambers are a large area (3×3m2), a self-supporting structure made of light composite materials and a low cost. A spatial resolution of 150?m has been achieved with a single hit efficiency

M G Anfreville; Pierre Astier; M. Authier; Alberto Baldisseri; M. Banner; N. Besson; J. Bouchez; A. Castera; O. Cloué; J. Dumarchez; E. Gangler; J. Gosset; C. Hagner; C. Jollec; C. Lachaud; A A Letessier-Selvon; J.-M Levy; Lucie Linssen; J.-P Meyer; J.-P Ouriet; J.-P Passérieux; T. Pedrol Margaley; Alfredo Placci; A. Pluquet; J. Poinsignon; B. A Popov; P. Rathouit; K. Schahmaneche; T. Stolarczyk; V. Uros; F. Vannucci; M. K Vo; H. Zaccone

2002-01-01

262

Vapor chamber in high performance server  

Microsoft Academic Search

This article describes how to evaluate the thermal-performance of vapor chamber-based thermal module, which has existed in the thermal-module industry for a year or so especially in server application. Thermal-performance of the thermal module with the vapor chamber can be determined within several seconds by using the final formula associated with thermal-performance experimental method deduced in this paper. From the

Jung-Chang Wang; Teng-Chieh Chen

2009-01-01

263

Combustion chamber layout for modern Otto engines  

SciTech Connect

Since the most efficient way to improve fuel economy in the part-load range is to increase the compression ratio, emphasis is placed on combustion chambers allowing high compression ratios combined with low octane requirements. According to Porsche experience, many demands can be met in the simplest manner by locating the combustion chamber in the piston crown. This configuration offers various advantages over its counterpart installed in the cylinder head. 24 refs.

Gruden, D.O.

1981-10-01

264

Anterior chamber intraocular lens for high myopia  

Microsoft Academic Search

Purpose: To evaluate the effectiveness of the surgical correction of high myopia 5 years after anterior chamber intraocular lens (IOL) implantation and to analyze the lens position and related complications.Setting: Federal University of São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.Methods: This prospective study comprised 26 eyes that were implanted with an anterior chamber IOL (model ZB5M) and had a

Renate Ferreira de Souza; Adriana Forseto; Regina Nosé; Rubens Belfort; Walton Nosé

2001-01-01

265

Facility “wellness”: health facilities management  

Microsoft Academic Search

Hospitals and health-care facilities are among the most complex, costly, and challenging buildings to design, construct and manage. To become a health facilities manager of a hospital or other medical centre in the USA, one requires knowledge not only of how to manage people, but also of how to deal with government agencies and all kinds of regulations and inspections.

Frank Moy Jr

1995-01-01

266

The next step in chemical propulsion: Oxide-iridium/rhenium combustion chambers  

SciTech Connect

Chemical propulsion systems are currently limited by materials issues. Until recently, the state-of-the-art material for liquid propellant combustion chambers was silicide-coated niobium. However, combustion chamber performance demands have exceeded the capabilities of this material system, requiring development of better materials. The iridium/rhenium combustion chamber, comprising a rhenium structural shell with an iridium inner liner for oxidation protection, represents the current state of the art in high-performance, high temperature, long-life propulsion systems using nitrogen tetroxide/monomethyl hydrazine propellant. However, oxygen/hydrogen (O{sub 2}/H{sub 2}) and new 'green' monopropellants under development to replace hydrazine will be significantly more oxidizing at operating temperature. For these more highly aggressive combustion environments, Ultramet has shown that substantial additional life can be obtained by lining the interior of the combustion chamber with a refractory metal oxide, which functions as a thermal and gas diffusion barrier and provides dramatically increased oxidation resistance. Ultramet has fabricated numerous 22-N (5-lb{sub f}) thrust chambers with this oxide-iridium/rhenium architecture that have been hot-fire tested at NASA Lewis Research Center in O{sub 2}/H{sub 2} propellant at mixture ratios of 6 and 16, with steady-state exterior wall temperatures ranging from 2433 to 2899 K, comprising the most severe temperature and oxidizing conditions ever utilized. Of the seven chambers tested to date, three failed due to facility problems, and two never failed. The best-performing chamber was hot-fired for 13,595 seconds (227 minutes; 3.8 hours) and showed no visible signs of degradation. Additional chambers are being fabricated for future testing.

Fortini, Arthur J.; Tuffias, Robert H. [Ultramet, 12173 Montague St., Pacoima, California 91331 (United States)

1999-01-22

267

Magma chamber paradox: decompression upon replenishment  

NASA Astrophysics Data System (ADS)

The invasion of active magma chambers by fresh magma of deeper provenance is invariably assumed to cause chamber pressurization. Pressure increase thus stands as an intuitive consequence of magma chamber replenishment. However, new numerical simulations demonstrate that pressure evolution is highly non-linear, and that decompression dominates when large density contrasts exist between injected and resident magmas. This apparent paradox originates from the compressible nature of volatile-rich magma and the dynamics of convection associated with injections of buoyant magma. While decompression can dominate in a shallow chamber, pressure increase develops in the connected deep regions of magma provenance. These results contradict classical views adopted to interpret observations at active as well as fossil magma chambers, and demonstrate that a simple reliance on intuition is insufficient: what may be perceived as a paradox - magma chamber decompression upon replenishment - is instead likely, and rooted in the complex physics that governs the multiphase, multi-component dynamics of magma transport in geometrically composite, spatially extended magmatic systems.

Papale, Paolo; Longo, Antonella; Montagna, Chiara Paola

2013-04-01

268

Chamber, target and final focus integrated design  

NASA Astrophysics Data System (ADS)

Liquid wall protection, which challenges chamber clearing, has advantages in Heavy Ion Fusion's (HIF) main line chamber design. Thin liquid protection from X-rays is necessary to avoid erosion of structural surfaces and thick liquid makes structures behind 0.5m of flibe (7 mean free paths for 14MeV neutrons), last the life of the plant. Liquid wall protection holds the promise of greatly increased economic competitiveness. The illumination must be compatible with liquid wall protection. The ``best'' values for driver energy, gain, yield and pulse rate comes out of well-known trade-off studies to arrive at the minimum cost of electricity. In order to reduce the driver cost and therefore reduce the cost of electricity, driver designers are attempting to reduce driver energy from the old 10GeV value and increase the number of beams to about 200 to illuminate recent target designs from two sides. We have not yet succeeded in coming up with an integrated chamber design compatible with 200 beams. The present design iteration and future ones will depend on several key assumptions, such as jet surface smoothness and rapid chamber clearing. Before HIF can be considered feasible and economical, we need an integrated chamber, target, and final focus design and successful resolution of key technical issues by the chamber R&D efforts.

Moir, R. W.

2001-05-01

269

12. View north of Tropic Chamber. Natick Research & ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. View north of Tropic Chamber. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

270

A Dedicated Facility to Perform Powder and Light Gas Gun Experiments  

NASA Astrophysics Data System (ADS)

A new building has been constructed to house various powder, single and two-stage gas guns at the Naval Surface Warfare Center, Indian Head. Guns previously located at the Naval Research Laboratory and the former White Oak Site of the Naval Surface Warfare Center have been relocated. Most of the guns are mounted on movable pedestals to allow them to be shot into various chambers. These chambers are a concrete blast chamber, a target chamber/catch tank for flyer plate experiments, and a target chamber outfitted for terminal ballistics measurements. This paper will discuss the capabilities of this new facility.

Zakraysek, A. J.; Sutherland, G. T.; Sandusky, H. D.

1999-06-01

271

Facility Planning.  

ERIC Educational Resources Information Center

This article reviews recommendations on policies for leasing surplus school space made during the Council of Educational Facility Planners/International conference. A case study presentation of a Seattle district's use of lease agreements is summarized. (MJL)

Graves, Ben E.

1984-01-01

272

Formability Facility.  

National Technical Information Service (NTIS)

A facility has been established which will allow experimental determination of the forming characteristics of sheet metals. These characteristics are determined by stretching a sheet to failure over a hemispherical punch. This report describes the facilit...

R. Salzbrenner P. Bortniak

1982-01-01

273

Health Facilities  

MedlinePLUS

Health facilities are places that provide health care. They include hospitals, clinics, outpatient care centers, and specialized care centers, such as birthing centers and psychiatric care centers. When you ...

274

Stability of A-150 plastic ionization chamber response over a ~30 year period  

SciTech Connect

At the NIU Institute for Neutron Therapy at Fermilab, the clinical tissue-equivalent ionization chamber response is measured every treatment day using a cesium source that was configured to match readings obtained at the National Bureau of Standards. Daily measurements are performed in air using the air-to-tissue dose conversion factors given in AAPM Report no. 7. The measured exposure calibration factors have been tabulated and graphed as a function of time from 1978 to present. For A-150 plastic ionization chambers, these factors exhibit a sinusoidal variation with a period of approximately one year and amplitude of {+-} 1%. This variation, attributable to the hygroscopic nature of A-150 plastic, is correlated with the relative humidity of the facility, and is greater than the humidity corrections for gas described in the literature. Our data suggest that chamber calibration should be performed at least weekly to accommodate these variations.

Kroc, Thomas K.; Lennox, Arlene J.; /Fermilab

2007-08-01

275

A single chamber stackable microbial fuel cell with air cathode.  

PubMed

A single chamber stackable microbial fuel cell (SCS-MFC) comprising four MFC units was developed. When operated separately, each unit generated a volumetric power density (P(max,V)) of 26.2 W/m(3) at 5.8 mA or 475 mV. The total columbic efficiency was 40% for each unit. Parallel connection of four units produced the same level of power output (P(max,V) of 22.8 W/m(3) at 27 mA), which was approximately four times higher than a single unit alone. Series connection of four units, however, only generated a maximum power output of 14.7 W/m(3) at 730 mV, which was less than the expected value. This energy loss appeared to be caused by lateral current flow between two units, particularly in the middle of the system. The cathode was found to be the major limiting factor in our system. Compared to the stacked operation of multiple separate MFCs, our single chamber reactor does not require a delicate water distribution system and thus is more easily implemented in pre-existing wastewater treatment facilities with serpentine flow paths, such as fixed-bed reactors, with minimal infrastructure changes. PMID:19034389

Wang, Bin; Han, Jong-In

2008-11-26

276

Motor Controls for the NIFFTE Time Projection Chamber Positioning Stand  

NASA Astrophysics Data System (ADS)

The next generation nuclear power plants will be more efficient and produce smaller amounts of radioactive waste. Design of these new reactors is limited partially by the lack of precise neutron induced fission cross sections at certain incident neutron energies of several isotopes. In order to reduce the uncertainty of the cross sections to less than 1 percent, a Time Projection Chamber (TPC) was built by the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration. These improvements in precision will be possible due to the TPC's ability for a full 3-D reconstruction of the fission fragment tracks. The NIFFTE TPC will be installed at Los Alamos National Lab's LANSCE facility. Thin targets will be mounted in the center of the TPC in a pressurized hydrogen gas chamber so that both hemispheres of the reaction will be covered. In this work we will discuss the control of the stepper motors that drive the positioning table of the TPC, which has all of its readout electronics attached, to be lined up with the beam. This includes both the controlling software and its graphical interface to the MIDAS online data acquisition system.

Pamplin, Daniel; Pickle, Nathan

2010-11-01

277

Motor Controls for the NIFFTE Time Projection Chamber Positioning Stand  

NASA Astrophysics Data System (ADS)

The next generation nuclear power plants will be more efficient and produce smaller amounts of radioactive waste. Design of these new reactors is limited partially by the lack of precise neutron induced fission cross sections at certain incident neutron energies of several isotopes. In order to reduce the uncertainty of the cross sections to less than 1%, a Time Projection Chamber (TPC) was built by the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration. These improvements in precision will be possible due to the TPC's ability for a full 3-D reconstruction of the fission fragment tracks. The NIFFTE TPC will be installed at Los Alamos National Lab's LANSCE facility. Thin targets will be mounted in the center of the TPC in a pressurized hydrogen gas chamber so that both hemispheres of the reaction will be covered. This talk considers the control of the stepper motors that drive the positioning table of the TPC, which has all of its readout electronics attached, to be lined up with the beam. This includes both the controlling software and its graphical interface to the MIDAS online data acquisition system.

Pamplin, Daniel; Pickle, Nathan

2010-10-01

278

Design characteristics of a heat pipe test chamber  

NASA Astrophysics Data System (ADS)

LeRC has designed a heat pipe test facility which will be used to provide data for validating heat pipe computer codes. A heat pipe test chamber that uses helium gas for enhancing heat transfer was investigated. The conceptual design employs the technique of guarded heating and guarded cooling to facilitate accurate measurements of heat transfer rates to the evaporator and from the condenser. The design parameters are selected for a baseline heat pipe made of stainless steel with an inner diameter of 38.10 mm and a wall thickness of 1.016 mm. The heat pipe operates at a design temperature of 1000 K with an evaporator radial heat flux of 53 W/sq. cm.

Baker, Karl W.; Jang, J. Hoon; Yu, Juin S.

1992-07-01

279

National Ignition Facility system alignment.  

PubMed

The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37?cm square beams, each generating up to 9.6?kJ of 351?nm laser light in a 20?ns beam precisely tailored in time and spectrum. The Facility houses a massive (10?m diameter) target chamber within which the beams converge onto an ?1?cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5?m×2?m×1?m) line-replaceable optics assemblies to within ±1?mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10?min and alignment to target chamber center within 44?min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50??m rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams. PMID:21394186

Burkhart, S C; Bliss, E; Di Nicola, P; Kalantar, D; Lowe-Webb, R; McCarville, T; Nelson, D; Salmon, T; Schindler, T; Villanueva, J; Wilhelmsen, K

2011-03-10

280

Chamber, Target and Final Focus Integrated Design  

SciTech Connect

Liquid wall protection, which challenges chamber clearing, has such advantages it's Heavy Ion Fusion's (HIF) main line chamber design. Thin liquid protection from x rays is necessary to avoid erosion of structural surfaces and thick liquid makes structures behind 0.5 m of Flibe (7 mean free paths for 14 MeV neutrons), last the life of the plant. Liquid wall protection holds the promise of greatly increased economic competitiveness. Driver designers require {approx}200 beams to illuminate recent target designs from two sides. The illumination must be compatible with liquid wall protection. The ''best'' values for driver energy, gain, yield and pulse rate comes out of well-known trade-off studies. An integrated chamber design, yet to be made, depends on several key assumptions, which are to be proven before HIF can be shown to be feasible. The chamber R&D needed to reduce the unknowns and risks depend on resolving a few technical issues such as jet surface smoothness and rapid chamber clearing.

Moir, R.W

2000-03-22

281

Chamber, Target and Final Focus Integrated Design  

SciTech Connect

Liquid wall protection, which challenges chamber clearing, has such advantages it's Heavy Ion Fusion's (HIF) main line chamber design. Thin liquid protection from x rays is necessary to avoid erosion of structural surfaces and thick liquid makes structures behind 0.5 m of Flibe (7 mean free paths for 14 MeV neutrons), last the life of the plant. Liquid wall protection holds the promise of greatly increased economic competitiveness. Driver designers require {approx}200 beams to illuminate recent target designs from two sides. The illumination must be compatible with liquid wall protection. The ''best'' values for driver energy, gain, yield and pulse rate comes out of well-known trade-off studies. The chamber design is based on several key assumptions, which are to be proven before HIF can be shown to be feasible. The chamber R&D needed to reduce the unknowns and risks depend on resolving a few technical issues such as jet surface smoothness and rapid chamber clearing.

Moir, R.W.

2000-03-03

282

[Inhospital thrombolism of right cardiac chambers].  

PubMed

Veins of lower extremities are classic sources of pulmonary artery thromboembolism (PATE). But one should not underestimate presence of thrombi in other potential sources - veins of small pelvis, superior vena cava, and chambers of the heart. We analyzed 652 case histories and autopsy data of patients in whom PATE had been revealed at pathological anatomical investigation and selected 157 cases in which right heart chambers were sources of emboli (right atrium in 83.5% and right ventricle - in 13.7% of cases). According to autopsy data average mass of the heart was 512.5+/-36.1 g. In most patients it exceeded norm. Thrombi in both right and left cardiac chambers were found in 52.3% of cases. Eighty three patients had history of myocardial infarction or were treated for MI during last hospitalization; 52.3% of patients had atrial fibrillation. After detailed study of all anamnestic, clinical, instrumental, and pathologic-anatomic data we selected 69 factors which according to contemporary views could facilitate formation of thrombus in the right cardiac chambers. Using these factors and method of logistic regression we created a mathematical model for assessment of probability of the presence of thrombi in right cardiac chambers. PMID:23953045

Vasil'tseva, O Ia; Vorozhtsova, I N; Karpov, R S

2013-01-01

283

Sandia National Laboratories' new high level acoustic test facility  

NASA Astrophysics Data System (ADS)

A high intensity acoustic test facility has been designed and is under construction at Sandia National Laboratories in Albuquerque, NM. The chamber is designed to provide an acoustic environment of 154dB (re 20 microPa) overall sound pressure level over the bandwidth of 50 Hz to 10,000 Hz. The chamber has a volume of 16,000 cubic feet with interior dimensions of 21.6 ft x 24.6 ft x 30 ft. The construction of the chamber should be complete by the summer of 1990. The design goals and constraints of the facility are discussed. The construction characteristics are discussed in detail, as are the acoustic performance design characteristics. The authors hope that this work will help others in designing acoustic chambers.

Rogers, Jonathan D.; Hendrick, David M.

284

A comparison between the outgassing process of a titanium chamber and a stainless steel chamber  

Microsoft Academic Search

A vacuum chamber made from TiN coated titanium and a vacuum chamber made from electropolished stainless steel were pumped down with the bakeout process at temperatures of 150 °C, 200 °C, 250 °C and 300 °C. The time (t) dependence of the total pressure (P) at each bakeout temperature was described as P = A · t?0.2 for the electropolished

Michio Minato; Yoshio Itoh

1996-01-01

285

Osteogenesis by human osteoblastic cells in diffusion chamber In vivo  

Microsoft Academic Search

Osteogenic potential of osteoblastic cells isolated from human bone was evaluated by a diffusion chamber method. Cells placed in diffusion chambers were implanted intraperitcneally into the athymic mice. The diffusion chambers cultured in vivo were harvested and examined after implantation for 6–8 weeks. The content of the chamber was proved by a soft roentogenogram to contain the radioopaque area. Light

Y. Gotoh; K. Fujisawa; K. Satomura; M. Nagayama

1995-01-01

286

A new extended-length parallel-plate ionization chamber  

Microsoft Academic Search

A special parallel-plate ionization chamber was developed. The motivation for the construction of this new chamber was mainly to fulfil the need of a reference system for computed tomography standard beams in the Calibration Laboratory of IPEN. However, the chamber was tested also in standard radiation beams of mammography and conventional diagnostic radiology. The chamber was manufactured at the institute

Ana F Maia; Linda V E Caldas

2005-01-01

287

Numerical Simulation on Forced Swirl Combustion Chamber in Diesel Engine  

Microsoft Academic Search

A concept of forced swirl combustion chamber in diesel engine is proposed in this paper. It can be used to enhance the intensity of swirl flow in the cylinder and accelerate the rate of air-fuel mixture process by designing the special structure in the combustion chamber. This new type of forced swirl combustion chamber includes double swirl combustion chamber that

Shang Yong; Liu Fu-shui; Li Xiang-rong

2011-01-01

288

Numerical Simulation on Forced Swirl Combustion Chamber in Diesel Engine  

Microsoft Academic Search

A concept of forced swirl combustion chamber in diesel engine is proposed in this paper. It can be used to enhance the intensity of swirl flow in the cylinder and accelerate the rate of air-fuel mixture process by designing the special structure in the combustion chamber. This new type of forced swirl combustion chamber includes double swirl combustion chamber that

Shang Yong; Liu Fu-shui; Li Xiang-rong

2010-01-01

289

BPSG boron spike generation investigated by chamber pressure monitoring  

Microsoft Academic Search

Mechanism of boron spike generation in BPSG film is discussed. Process chamber pressure traces are monitored when individual source gases are introduced. Changes in BPSG dopant profile due to differing chamber conditions can be identified by a simple method of monitoring the chamber pressure level. The mechanism of the boron spike is explained. The chamber conditions can be controlled by

Toshiya Yokota; Takamichi Yamaura; Kuniaki Orikasa; Masayuki Higashimoto; Akihiko Ishida

2008-01-01

290

Secondary Combustion in a Dual-Chamber Woodstove.  

National Technical Information Service (NTIS)

The paper discusses laboratory tests of a modified, popular dual-chamber woodstove to determine its ability to reduce emissions. In dual-chamber stoves, the primary chamber is for fuel volatilization, and the secondary chamber is for combustion. The origi...

G. A. Spolek R. E. Hall J. H. Wasser

1988-01-01

291

Chamber LIDAR measurements of aerosolized biological simulants  

NASA Astrophysics Data System (ADS)

A chamber aerosol LIDAR is being developed to perform well-controlled tests of optical scattering characteristics of biological aerosols, including Bacillus atrophaeus (BG) and Bacillus thuringiensis (BT), for validation of optical scattering models. The 1.064 ?m, sub-nanosecond pulse LIDAR allows sub-meter measurement resolution of particle depolarization ratio or backscattering cross-section at a 1 kHz repetition rate. Automated data acquisition provides the capability for real-time analysis or recording. Tests administered within the refereed 1 cubic meter chamber can provide high quality near-field backscatter measurements devoid of interference from entrance and exit window reflections. Initial chamber measurements of BG depolarization ratio are presented.

Brown, David M.; Thrush, Evan P.; Thomas, Michael E.; Siegrist, Karen M.; Baldwin, Kevin; Quizon, Jason; Carter, Christopher C.

2009-05-01

292

[Influence of grave chamber systems on decomposition].  

PubMed

Grave chambers allow bodies to decompose independent of hydrogeological circumstances. We examined the degree of body decomposition in 11 grave chambers after burial times between 12.1 and 15.3 years (mean 13.0 years). In 8 of the examined 11 bodies, bones were separated due to complete loss of tissue continuity. In 3 cases, the graves were partly not properly constructed and tissue continuity was at least partially preserved. Biochemical estimation of the age at the time of death on the basis of six teeth gathered during the inspection of the grave chambers showed only one result that could not be explained by the standard deviation of the method used. PMID:23136700

Hartung, Benno; Matzenauer, Christian; Ritz-Timme, Stefanie

293

Radon progeny behavior in diffusion chamber  

NASA Astrophysics Data System (ADS)

The behavior of short-lived radon progeny in a diffusion chamber was modeled based on the random Brownian motion and diffusion. The modeling enables calculations of the fraction of radon progeny that decays in air, as well as, the distribution of the atoms deposited onto the inner walls of the diffusion chamber. Up to 23% of 218Po decays in air, while 214Pb and 214Bi are almost fully deposited before decaying. The distribution of deposited progeny was found to be non-uniform. In the second part of the paper, deposition of charged progeny atoms was also considered. The influence of non-uniform deposition of radon progeny on the total sensitivity was investigated for an LR 115 detector in one typical diffusion chamber. The electric charge increases the deposition of radon progeny.

Nikezi?, D.; Stevanovi?, N.

2005-10-01

294

Simulation of BaBar Drift Chamber  

SciTech Connect

The BaBar drift chamber (DCH) is used to measure the properties of charged particles created from e{sup +}e{sup -} collisions in the PEP-II asymmetric-energy storage rings by making precise measurements of position, momentum and ionization energy loss (dE/dx). In October of 2005, the PEP-II storage rings operated with a luminosity of 10 x 10{sup 33} cm{sup -2}s{sup -1}; the goal for 2007 is a luminosity of 20 x 10{sup 33} cm{sup -2}s{sup -1}, which will increase the readout dead time, causing uncertainty in drift chamber measurements to become more significant in physics results. The research described in this paper aims to reduce position and dE/dx uncertainties by improving our understanding of the BaBar drift chamber performance. A simulation program--called GARFIELD--is used to model the behavior of the drift chamber with adjustable parameters such as gas mixture, wire diameter, voltage, and magnetic field. By exploring the simulation options offered in GARFIELD, we successfully produced a simulation model of the BaBar drift chamber. We compared the time-to-distance calibration from BaBar to that calculated by GARFIELD to validate our model as well as check for discrepancies between the simulated and calibrated time-to-distance functions, and found that for a 0{sup o} entrance angle there is a very good match between calibrations, but at an entrance angle of 90{sup o} the calibration breaks down. Using this model, we also systematically varied the gas mixture to find one that would optimize chamber operation, which showed that the gas mixture of 80:20 Helium:isobutane is a good operating point, though more calculations need to be done to confirm that it is the optimal mixture.

Anderson, Rachel; /Wisconsin U., Eau Claire /SLAC

2006-09-27

295

Characteristics of a delay-line readout in a cylindrical drift chamber system  

NASA Astrophysics Data System (ADS)

This paper reports on the design, construction, and operational characteristics of a delay-line readout implemented on the cathode foils of a cylindrical drift chamber system. The readout was used to determine the position of an event along the length of the 1.74m drift wires in the MEGA detectors used at the Los Alamos Meson Physics Facility. The performance of the system is interpreted by comparison to a PSPICE simulation, and to simple analytical models.

Barber, R.; Ahmed, M. W.; Dzemidzic, M.; Empl, A.; Hungerford, E. V.; Lan, K. J.; Wilson, J.; Cooper, M. D.; Gagliardi, C. A.; Haim, D.; Kim, G. J.; Koetke, D. D.; Tribble, R. E.; Van Ausdeln, L. A.

2002-03-01

296

Threshold bubble chamber for measurement of knock-on DT neutron tails from magnetic and inertial confinement experiments  

SciTech Connect

We propose a new {open_quotes}threshold{close_quotes} bubble chamber detector for measurement of knock-on neutron tails. These energetic neutrons result from fusion reactions involving energetic fuel ions created by alpha knock-on collisions in tokamak and other magnetic confinement experiments, and by both alpha and neutron knock-on collisions in inertial confinement fusion (ICF) experiments. The energy spectrum of these neutrons will yield information on the alpha population and energy distribution in tokamaks, and on alpha target physics and {rho}R measurements in ICF experiments. The bubble chamber should only detect neutrons with energies above a selectable threshold energy controlled by the bubble chamber pressure. The bubble chamber threshold mechanism, detection efficiency, and proposed applications to the International Thermonuclear Experimental Reactor (ITER) and National Ignition Facility (NIF) experiments will be discussed.

Fisher, R.K. [General Atomics, San Diego, CA (United States); Zaveryaev, V.S. [Russian Research Centre, Moscow (Russian Federation). Kurchatov Institute; Trusillo, S.V. [Russian Federal Nuclear Centre, Arzamas (Russian Federation). Experimental Physics Institute

1996-07-01

297

Simulation, design, and construction of a 137Cs irradiation facility.  

PubMed

Regulatory entities require that for any radiation facility the surrounding areas must be restricted unless the dose equivalent is less than 0.02 mSv in any one hour. Two Monte Carlo radiation transport simulation codes, MCNP5 and Mercurad, were used to design a facility to shield a 3.48 x 10(5) MBq 137Cs irradiator that meets these requirements. Simulations showed that the dose equivalent rates were below the legal limit for unrestricted access and the facility was constructed using available concrete block and student labor to minimize costs. To verify the accuracy of the Monte Carlo radiation transport codes, an ion chamber was used to characterize the facility. Ion chamber measurements in the actual, as-built irradiation facility showed that the Monte Carlo codes, MCNP5 and Mercurad, agreed by a factor of better than 6% and better than 11%, respectively. PMID:17440327

Studenski, Matthew T; Haverland, Nathan P; Kearfott, Kimberlee J

2007-05-01

298

In-vacuum target transfer facility  

NASA Astrophysics Data System (ADS)

In order to transfer highly oxidizing and hygroscopic targets in-vacuum or in controlled atmosphere and to change the target ladder without affecting the chamber vacuum, an in-vacuum target transfer system has been designed, fabricated and installed. It consists of a transfer body, compatible flanges with gate valves at the bell jar and the chamber. Ca, being a highly oxidizing element, was taken as a test case to stress the utility of the in-vacuum target transfer system. Using the elastic recoil detection analysis (ERDA) technique, we could see that there was only 11.5% of O2 in the target when it was transferred from the bell jar to the scattering chamber using the in-vacuum target transfer facility. When the target was exposed to air for 35 min the O2 content rose to 63.5 at.%

Kabiraj, D.; Mandal, Samit; Avasthi, D. K.

1995-02-01

299

Music Facilities.  

ERIC Educational Resources Information Center

|The layouts and specifications in this booklet are intended to assist those involved in planning music facilities for elementary and secondary schools. Drawings, room plans, and text illustrate specifications for location; space relationship; combined and separate instrumental and vocal rooms; practice rooms; and auxiliary areas. Particular…

Ontario Dept. of Education, Toronto. School Planning and Building Research Section.

300

Facilities Management.  

ERIC Educational Resources Information Center

Presents responses from Matt McGovern, "School Planning and Management's" Maintenance and Operations columnist, on the issue of school facility maintenance. McGovern does not believe schools will ever likely meet acceptable levels of maintenance, nor use infrared thermography for assessing roofs, outsource all maintenance work, nor find a pressing…

Bete, Tim, Ed.

1998-01-01

301

Facilities Manager.  

ERIC Educational Resources Information Center

Presents a series of articles that cover a range of issues with regard to the Association of Higher Education Facilities Officers. Papers explore ways to balance natural and human settings, provide an overview of a professional leadership academy, describe the preparations for an effectiveness skills program, and outline some of the concerns…

Facilities Manager, 1998

1998-01-01

302

Facilities Management.  

ERIC Educational Resources Information Center

|Presents responses from Matt McGovern, "School Planning and Management's" Maintenance and Operations columnist, on the issue of school facility maintenance. McGovern does not believe schools will ever likely meet acceptable levels of maintenance, nor use infrared thermography for assessing roofs, outsource all maintenance work, nor find a…

Bete, Tim, Ed.

1998-01-01

303

Simulation by Monte Carlo Method of Power Varying with Time Detected by Fission Chamber in TRACY Water-Reflected System  

Microsoft Academic Search

Numerical simulation of power varying with time detected by fission chamber was performed using the continuous-energy Monte Carlo code MCNP4B to comprehend time delay of neutron detection in power burst experiments arranged for systems incorporating water reflector as well as devoid of reflector in the Transient Experiment Critical Facility (TRACY). The simulation indicated that power generation in core during an

Hiroshi YANAGISAWA; Akio OHNO

2002-01-01

304

Simulation by Monte Carlo Method of Power Varying with Time Detected by Fission Chamber in TRACY Water-Reflected System  

Microsoft Academic Search

Numerical simulation of power varying with time detected by fission chamber was performed using the continuous- energy Monte Carlo code MCNP4B to comprehend time delay of neutron detection in power burst experiments arranged for systems incorporating water reflector as well as devoid of reflector in the Transient Experiment Critical Facility (TRACY). The simulation indicated that power generation in core during

Hiroshi YANAGISAWA; Akio OHNO

2002-01-01

305

On-line noise monitoring at the Fast Flux Test Facility  

SciTech Connect

An automated noise surveillance and diagnostics system (ANSDS) is being demonstrated at the Fast Flux Test Facility (FFTF). Three low-level, in-vessel fission chambers (LLFMs), three ex-vessel compensated ion chambers (CICs), and two accelerometers on the mechanism of one advanced absorber (ADVAB) control rod were monitored with an automated noise surveillance and diagnostic system (ANSDS) in late 1983.

Mullens, J.A.; Thie, J.A.; Campbell, L.R.

1984-01-01

306

Facilities and Techniques for Maintaining a Controlled Fluoride Environment in Vegetation Studies  

Microsoft Academic Search

Facilities, equipment, and techniques that have been developed by the US Steel Corporation to study the effects of fluorides on plants are described. Considerable care has been exercised to maintain conditions in the environmental chambers comparable to those in the field outside. The design of greenhouses and portable environmental chambers is described, as are measuring techniques used to determine air

A. C. Hill; L. G. Transtrum; M. R. Pack; A. Jr. Holloman

1959-01-01

307

FFTF (Fast Flux Test Facility) Reactor Characterization Program: Absolute Fission-rate Measurements  

Microsoft Academic Search

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of ²³²Th, ²³³U, ²³U, ²³U, ²³Np, ²³Pu, ²°Pu, and ²¹Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

J. L. Fuller; D. M. Gilliam; J. A. Grundl; J. A. Rawlins; J. W. Daughtry

1981-01-01

308

FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS  

Microsoft Academic Search

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of ²³²Th, ²³³U, ²³U, ²³U, ²³Np, ²³Pu, ²°Pu, and ²¹Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

1981-01-01

309

THE NOAA/EPA FLUID MODELING FACILITY'S CONTRIBUTIONS TO THE UNDERSTANDING OF THE ATMOSPHERIC DISPERSION  

EPA Science Inventory

Over the past thirty years, scientists at the Environmental Protection Agency's (EPA) Fluid Modeling Facility (FMF) have conducted laboratory studies of fluid flow and pollutant dispersion within three distinct experimental chambers: a meteorological wind tunnel, a water-channel ...

310

LDCM TIRS: Cracking open the chamber  

NASA Video Gallery

Engineers at Goddard Space Flight Center inspect and move the Thermal Infrared Sensor (TIRS) after two months of testing in the thermal vacuum chamber. TIRS completed its first round of thermal vacuum testing on Tuesday, October 4, marking the first time engineers evaluated the fully-assembled instrument at its normal operating temperature.

gsfcvideo

2011-10-31

311

Neutron irradiation test on ATLAS MDT chambers  

Microsoft Academic Search

The Monitored Drift Tubes (MDT) chambers of the ATLAS muon spectrometer are crucial for the identification of high-momentum final-state muons, which represent very promising and robust signatures of physics at the LHC. They will operate in a high rate and high background environment and therefore their performances should not significantly degrade for the whole ATLAS data taking. The maximum expected

P. Branchini; S. Di Luise; E. Graziani; C. Mazzotta; E. Meoni; G. Morello; A. Passeri; F. Petrucci; A. Policicchio; D. Salvatore; M. Schioppa

2007-01-01

312

Depth of ionization chamber in water  

Microsoft Academic Search

The device developed by the authors and described here enables the user to measure the depth from the water surface to the point of measurement for a cylindrical ion chamber with a waterproof plastic cap in a water phantom, free of surface-tension error with a high precision. The device seeks vertical orientation and provides the convenience of hands-free operation. The

R. C. Tailor; V. M. Tello

1995-01-01

313

STUDY ON STEM LEAKAGE OF IONIZATION CHAMBER  

Microsoft Academic Search

Tests were carried out to measure the radiation dosages in order to ; estimate and minimize the range of error due to stem leakage. Several types of x ; rays and Co⁶° gamma rays were measured by a Victoreen condenser. Results ; obtained when the whole chamber was irradiated were compared against those ; obtained by irradiating only the ionization

M. Nakamura; N. Koda; T. Kato

1962-01-01

314

Outgassing of thin wall stainless steel chamber  

Microsoft Academic Search

Stainless steel with its unique mechanical properties is the most frequently used material for manufacturing of vacuum chambers and components. Its disadvantage is hydrogen outgassing which makes obtaining of ultrahigh vacuum (UHV) troublesome. Vacuum annealing, prolonged in situ bake out, air bake, low-permeable coatings, and other, usually expensive methods, are applied to reduce the outgassing rate and the concentration of

V Nemani?; T Bogataj

1998-01-01

315

Hybrid numerical modelling of reverberation chambers  

Microsoft Academic Search

This paper describes recent advancements in hybrid numerical modelling of reverberation chambers (RCs). Motivation of modelling an RC is first described, and challenges in RC modelling are pointed out. Shortcomings and advantages of conventional numerical methods are discussed, and hybrid techniques are introduced to overcome disadvantages of different numerical methods while retaining their respective strengths. Benefits of hybrid methods are

Huapeng Zhao; Zhongxiang Shen; Erping Li

2012-01-01

316

Particle control in dielectric etch chamber  

Microsoft Academic Search

A methodology for evaluating and controlling particle performance in a dielectric etch system is developed and presented. Analysis of particle samples, collected from premature chamber failures for out-of-control particle levels, suggests sputtering of the upper electrode during etching is a key modulator to this problem. To eliminate such sputtering, we designed a series of experiments with the objective of identifying

Makarem A. Hussein; Robert B. Turkot

2006-01-01

317

Suppressing drift chamber diffusion without magnetic field  

Microsoft Academic Search

The spatial resolution in drift chamber detectors for ionizing radiation is limited by diffusion of the primary electrons. A strong magnetic field along the drift direction is often applied (Fancher et al., Nucl. Instr. and Meth. A 161 (1979) 383) because it suppresses the transverse diffusion, improving the resolution but at considerable increase in cost and complexity. Here we show

C. J. Martoff; D. P. Snowden-Ifft; T. Ohnuki; N. Spooner; M. Lehner

2000-01-01

318

Isolation of Drosophila egg chambers for imaging.  

PubMed

The fruit fly Drosophila melanogaster is an important model for basic research into the molecular mechanisms underlying cell function and development, as well as a major biomedical research tool. A significant advantage of Drosophila is the ability to apply live cell imaging to a variety of living tissues that can be dissected and imaged in vivo, ex vivo, or in vitro. Drosophila egg chambers, for example, have proven to be a useful model system for studying border cell migration, Golgi unit transport, the rapid movement of mRNA and protein particles, and the role of microtubules in meiosis and oocyte differentiation. A crucial first step before imaging is preparation of the experimental material to ensure physiological relevance and to achieve the best conditions for image quality. Early- to mid-stage egg chambers cannot be mounted in an aqueous-based medium, because this causes a change in microtubule organization and follicle cell morphology. Such egg chambers survive better in Halocarbon oil, which allows free diffusion of oxygen, has low viscosity, and thus prevents dehydration and hypoxia. With a refractive index similar to glycerol, Halocarbon oil also has good optical properties for imaging. It also provides a good environment for injection and is particularly useful for long-term imaging of embryos. However, unlike with aqueous solutions, changes in the medium are not possible. This protocol describes the isolation of Drosophila egg chambers. PMID:20360356

Parton, Richard M; Vallés, Ana Maria; Dobbie, Ian M; Davis, Ilan

2010-04-01

319

Monitoring the Atmosphere in an Anaerobic Chamber  

PubMed Central

The Couloximeter, a fuel cell designed to measure trace amounts of oxygen, was used to monitor the atmosphere in an anaerobic chamber. The device, easy to operate and to maintain, allowed both major and minor fluctuations in oxygen concentration to be measured. Using a hose attached to the outlet within the box, defective (ruptured) gloves were consistently distinguishable from intact gloves.

Sudo, Sara Z.; Hersch, Paul A.

1974-01-01

320

Susceptibility of small reverberation chamber investigation  

Microsoft Academic Search

The aim of this article is to investigate impact of geometrical design on uniformity of E-field distribution inside the small reverberation chamber. Results are demonstrated on numerical experiments made using FEKO computer code. The SRC is designed for measurements of handset terminals of mobile communications.

Wojciech J. Krzysztofik

2009-01-01

321

OUTDOOR SMOG CHAMBER EXPERIMENTS USING AUTOMOBILE EXHAUST  

EPA Science Inventory

Outdoor smog chamber experiments using automobile exhaust were performed in this study. The purpose of the study was to provide a data base that modelers could use to develop new, improved mechanisms for use in the Empirical Kinetics Modeling Approach (EKMA). Thirty-three dual sm...

322

Status report on a luminescent chamber  

Microsoft Academic Search

A magnetically focused 4-stage image intensifier was built for ; luminescent chamber experiments. Sandwich films consisting of phosphor screen, ; glass film, and photocathode surface were used. The image diameter of the tube ; is 3 cm. The light amplification is about 10⁶. A homogeneous axial ; magnetic field of 1500 gauss was used, so that the electron helix-diameter ;

O. Gildemeister; R. Giese

1963-01-01

323

VALIDATION OF A NEW DISPOSABLE COUNTING CHAMBER  

Microsoft Academic Search

In a routine prospective study, 3 different counting chambers were compared for manual and computer- assisted evaluations. Swim-up samples were used so as to remove all debris and other cells that may contaminate the evaluation process when using a semen analyzer. The Makler concentration determina- tions (n = 20) were, on average, approximately 20 ? 10 6 cells\\/mL higher compared

K. Coetzee; R. Menkveld

2001-01-01

324

A Storage Humidity Chamber for Hemocytometers.  

National Technical Information Service (NTIS)

When a series of hemocytometers is filled and stored prior to multiple counting, the chambers dry rapidly. In order to prevent this, a rack was designed which could accommodate 5 slides and minimize the possibility of errant counts due to desiccation. Ind...

W. F. Blatt H. A. Segal J. L. Gray

1965-01-01

325

Heterogeneous Catalysis in the Diesel Combustion Chamber  

Microsoft Academic Search

Results have been reported recently suggesting that the use of a platinum-coated combustion chamber would significantly reduce gaseous and particulate emissions in a diesel engine. To examine these claims, a single-cylinder version of a conventional automotive diesel engine was tested with and without a platinum coating. For all conditions tested, application of the coating resulted in no significant changes in

DONALD C. SIEGLA; STEVEN L PLEE

1982-01-01

326

Presenting Chamber Music to Young Children  

ERIC Educational Resources Information Center

|The number of professional ensembles and organizations with dedicated outreach concerts has been steadily increasing over the past decade. More recently, educational concerts pairing chamber music with young children have been documented. The work presented in this article is a study in the efficacy and feasibility of this format. Various music…

Smith, Terry Fonda

2011-01-01

327

A new extended-length parallel-plate ionization chamber  

NASA Astrophysics Data System (ADS)

A special parallel-plate ionization chamber was developed. The motivation for the construction of this new chamber was mainly to fulfil the need of a reference system for computed tomography standard beams in the Calibration Laboratory of IPEN. However, the chamber was tested also in standard radiation beams of mammography and conventional diagnostic radiology. The chamber was manufactured at the institute workshop, as simply and cheaply as possible. Its design differs from the common ionization chambers used in dosimetric procedures of computed tomography equipment, because it is a parallel-plate chamber instead of a cylindrical chamber. However, its dimensions and sensitive volume are very similar to those of a commercial pencil ionization chamber. The new ionization chamber was submitted to several characterization and quality control tests, showing its very good performance.

Maia, Ana F.; Caldas, Linda V. E.

2005-08-01

328

A new extended-length parallel-plate ionization chamber.  

PubMed

A special parallel-plate ionization chamber was developed. The motivation for the construction of this new chamber was mainly to fulfil the need of a reference system for computed tomography standard beams in the Calibration Laboratory of IPEN. However, the chamber was tested also in standard radiation beams of mammography and conventional diagnostic radiology. The chamber was manufactured at the institute workshop, as simply and cheaply as possible. Its design differs from the common ionization chambers used in dosimetric procedures of computed tomography equipment, because it is a parallel-plate chamber instead of a cylindrical chamber. However, its dimensions and sensitive volume are very similar to those of a commercial pencil ionization chamber. The new ionization chamber was submitted to several characterization and quality control tests, showing its very good performance. PMID:16077230

Maia, Ana F; Caldas, Linda V E

2005-08-02

329

The ENEA-IRP thoron calibration facility.  

PubMed

To check the consistency of a (220)Rn measurement, performed by passive alpha track detector (ATD), the use of an accurate (220)Rn exposure calibration facility is mandatory. The ENEA Radon Service developed a new CR-39 ATD-Tn, coupled to the radon ATD-Rn and, to assess its sensitivity, had to design a small calibration facility, which has been recently modified to improve the spatial homogeneity exposure conditions inside the chamber, to get a continuous monitoring of the (220)Rn concentration and to reduce radon contamination. A better knowledge of the circuit response allowed selecting the best-operating conditions and how to regulate the thoron concentration. The active thoron monitor has been changed to serve as a continuous sampling and measuring device rather than a grab one; particular care has been devoted to assess the (216)Po losses on the device's inner surfaces and to evaluate the chamber transit time correction factor. PMID:20846973

Calamosca, M; Penzo, S

2010-09-16

330

Instrumentation Design for HRR Measurements in a Large-Scale Fire Facility  

Microsoft Academic Search

Carleton University’s experimental atrium and tunnel facilities share a fan chamber and three large exhaust fans. Using oxygen\\u000a consumption calorimetry, the Heat Release Rates (HRR) of fires in either of these facilities can be calculated. This paper\\u000a focuses on the design of the instrumentation in the fan chamber, which was carried out using the Fire Dynamics Simulator (FDS)\\u000a and manual

Yoon J. Ko; Richard Michels; George V. Hadjisophocleous

2011-01-01

331

National Ignition Facility Project: An Update  

Microsoft Academic Search

The National Ignition Facility (NIT) consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component

W. J. Hogan; E. Moses; B. Warner; M. Sorem; J. Soures; J. Hands

2000-01-01

332

Modelling new particle formation from Jülich plant atmosphere chamber and CERN CLOUD chamber measurements  

NASA Astrophysics Data System (ADS)

An MALTE-BOX model is used to study the effects of oxidation of SO2 and BVOCs to new particle formation from Jülich Plant Atmosphere Chamber and CERN CLOUD chamber measurements. Several days of continuously measurements were chosen for the simulation. Our preliminary results show that H2SO4 is one of the critical compounds in nucleation process. Nucleation involving the oxidation of BVOCs shows better agreements with measurements.

Liao, Li; Boy, Michael; Mogensen, Ditte; Schobesberger, Siegfried; Franchin, Alessandro; Mentel, Thomas F.; Kleist, Einhard; Kiendler-Scharr, Astrid; Kulmala, Markku; dal Maso, Miikka

2013-05-01

333

A combination drift chamber\\/pad chamber for very high readout rates  

Microsoft Academic Search

Details of the construction of high-rate, mid-sized (1-m×2-m) pad chambers, intended for use in Fermi National Accelerator Laboratory (FNAL) experiment E-771, are described. Each gas volume module represents a chamber doublet: two identical anode wire planes, two transverse strip planes, and two pad planes. Wire signals, from 8-mm square cells, are recorded via TDCs; corresponding stripe and pad image signals

L. Spiegel; T. Alexopoulos; L. Antoniazzi; M. Arenton; C. Ballagh; H. Bingham; A. Blankman; M. Block; A. Boden; S. Borodin; J. Budagov; Z. L. Cao; G. Cataldi; T. Y. Chen; K. Clark; D. Cline; S. Conetti; M. Cooper; G. Corti; B. Cox; P. Creti; E. Dukes; C. Durandet; V. Elia; A. Erwin; L. Fortney; V. Golovatyuk; E. Gorini; F. Grancagnolo; M. Haire; P. Hanlet; M. He; G. Introzzi; M. Jenkins; J. Jennings; D. Judd; T. Kaeding; W. Kononenko; W. Kowald; A. Lanza; K. Lau; T. LeCompte; G. Liguori; J. Lys; P. Mazur; A. McManus; S. Misawa; G. Mo; C. T. Murphy; K. Nelson; M. Newcomer; M. Panareo; S. Ramachandran; M. Recagni; J. Rhoades; J. Rosen; J. Segal; W. Selove; R. P. Smith; J. Sun; S. Tokar; P. Torre; J. Trischuk; T. Trojak; E. Tsyganov; L. Turnbull; R. VanBerg; D. Wagoner; C. Wang; C. Wei; W. Yang; N. Yao; T. Yao; N. Zhang; S. N. Zhang; B. Zou

1991-01-01

334

A Perfusable 3D Cell-Matrix Tissue Culture Chamber for In Situ Evaluation of Nanoparticle Vehicle Penetration and Transport  

PubMed Central

A key factor in gene or drug therapy is the development of carriers that can efficiently reach targeted cells from a distal administration. In many gene/drug delivery studies, results obtained in 2D cultures fail to translate to similar results in vivo. In this work, we developed a perfu-sable 3D chamber for studying nanoparticle penetration and transport in cell–gel soft tissue cultures. The compartmented chamber is made of a polydimethylsiloxane (PDMS) top layer with the chamber features, created using micromachined lithography, bonded to a bottom glass coverslip. A solution of cells embedded in a hydrogel is loaded in the chamber between PDMS posts that serve as anchors to the cell–matrix at the gel-media interface. The chamber offers the following unique features: (i) rapid fabrication and simplicity in assembly, (ii) direct in situ cell imaging in a plane normal to the direction of flow or action, (iii) an easily configurable and controllable environment conducive cell culture under static or interstitial flow conditions, and (iv) facile recovery of live cells from chambers for post-experimental analysis. To assess the chamber, we delivered fluorescently labeled nanoparticles of three distinct sizes to cells-embedded Matrigels in the 3D chamber under flow and static conditions. Penetration of nanoparticles were enhanced under interstitial flow while live cell imaging and flow cytometry of recovered cells revealed particle size restrictions to efficient delivery. Although designed for delivery studies, the chamber is versatile and can be easily modified. Thus it may have broad applications for biological, tissue engineering, and therapeutic studies.

Ng, Chee Ping; Pun, Suzie Hwang

2009-01-01

335

Release of Reactive Halogen Species from Sea-Salt Aerosols under Tropospheric Conditions with\\/without the Influence of Organic Matter in Smog-Chamber Experiments  

Microsoft Academic Search

Experiments to investigate the release of reactive halogen species from sea-salt aerosol and the influence of organic matter were performed in an aerosol smog-chamber (3500 l), made of Teflon film (FEP 200A, Dupont). Smog chamber facilities at lowered temperature (coolable down to -25°C) enable us to simulate these reactions under polar, tropospheric conditions. First experiments were performed to investigate the

N. Balzer; W. Behnke; S. Bleicher; H. Krueger; J. Ofner; F. Siekmann; C. Zetzsch

2008-01-01

336

Gas Injection Apparatus for Vacuum Chamber  

SciTech Connect

We present in this article a gas injection apparatus which comprises the gas injector and its electronic command for vacuum chamber applications. Some of these applications are thin-film deposition by a pulsed laser deposition (PLD) or a cathodic arc deposition (arc-PVD) and the plasma generation. The electronic part has been developed to adjust the flow of the gas inside the vacuum chamber by controlling both of the injector's opening time and the repetition frequency to allow a better gas flow. In this case, the system works either on a pulsed mode or a continuous mode for some applications. In addition, the repetition frequency can be synchronised with a pulsed laser by an external signal coming from the laser, which is considered as an advantage for users. Good results have been obtained using the apparatus and testing with Argon and Nitrogen gases.

Almabouada, F.; Louhibi, D.; Hamici, M. [Centre de Developpement des Technologies Avancees CDTA, Division Milieux Ionises and Laser, BP 17, Cite du 20 Aout 1956, Baba Hassen, Alger (Algeria)

2011-12-26

337

Prototype vacuum chamber for compact SR ring  

SciTech Connect

A 650 MeV compact (3.14 m in circumference) superconducting electron storage ring is being developed as a synchrotron radiation light source for X-ray lithography. The vacuum system is designed to maintain a beam-on operating pressure of 1 x 10/sup -9/ Torr or less. This system has unique features. A prototype vacuum chamber has been fabricated and tested for evaluation of the vacuum system. A base pressure of 2.6 x 10/sup 10/ Torr (nitrogen equivalent) has been achieved. The pumping speed of the cryopump built into the chamber has been measured at 12000--17000 1/s for hydrogen gas. These results have confirmed to feasibility of this vacuum system for the SR ring.

Yasumitsu, N.

1988-09-30

338

Encounters: Chamber Piece for Eight Players  

Microsoft Academic Search

Encounters: Chamber Piece for Eight Players is a three-movement composition that was conceived as a dance piece. Though it features only eight instrumentalists, the wide range of timbres present in the ensemble creates a dramatic and theatrical effect suitable for a dance setting. The piece also functions effectively without dance.\\u000aEach of the three movements’ subtitles – Entrance, Apparition, and

Michael Stephen Hegedus

2005-01-01

339

Plant fumigation chamber suitable for forestry studies  

Microsoft Academic Search

A lean-to greenhouse with a volume of 8.4 m³ is being used to expose potted trees as tall as 2 m to air pollutants. Desired temperature is maintained by an air-conditioner and electric strip heaters. Pneumatic mist nozzles and steam are used to keep relative humidity at specified levels. Sunlight is used for illumination. Phytotoxicants, introduced into the chamber through

Charles R. Berry

1970-01-01

340

Vapor condensation study for HIF liquid chambers  

NASA Astrophysics Data System (ADS)

This paper presents the experimental study of transient cooling and condensation of the prototypical material flibe under conditions relevant to Heavy Ion Fusion (HIF) power plants. Superheated vapor is generated by a high-current, pulsed electrical discharge over a pool of liquid flibe. The excited vapor expands inside a temperature-controlled chamber designed to scale the initial density of the generated vapor, the initial energy density and the surface area available for condensation, considering HYLIFE-II as the reference design. Clearing rates are evaluated from the measured pressure history. Mass spectroscopy is used to characterize the composition of the residual gases. SEM analysis of material deposited on witness plates is also presented, showing that interface phenomena during the initial expansion phase depend on the orientation of the condensation surface relative to the gas velocity. The results show that chamber clearing can be characterized by an exponential decay with a time constant of 6.58 ms. However, the equilibrium pressure is one order of magnitude higher than the desired HIF base pressure because of the presence of non-condensable impurities dissolved in the material available for the experiments. If the exponential decay is applied to the pressure range of the reference design, the resulting period for chamber clearing is 60 ms. The conclusion is that condensation rates of flibe vapor are sufficiently fast to allow HIF power plants repetition rates, and that the main issue for flibe vapor condensation lies in the control of the impurities dissolved in the salt.

Calderoni, P.; Ying, A.; Sketchley, T.; Abdou, M. A.

2005-05-01

341

ORNL irradiation creep facility  

SciTech Connect

A machine was developed at ORNL to measure the rates of elongation observed under irradiation in stressed materials. The source of radiation is a beam of 60 MeV alpha particles from the Oak Ridge Isochronous Cyclotron (ORIC). This choice allows experiments to be performed which simulate the effects of fast neutrons. A brief review of irradiation creep and experimental constraints associated with each measurement technique is given. Factors are presented which lead to the experimental choices made for the Irradiation Creep Facility (ICF). The ICF consists of a helium-filled chamber which houses a high-precision mechanical testing device. The specimen to be tested must be thermally stabilized with respect to the temperature fluctuations imposed by the particle beam which passes through the specimen. Electrical resistance of the specimen is the temperature control parameter chosen. Very high precision in length measurement and temperature control are required to detect the small elongation rates relevant to irradiation creep in the test periods available (approx. 1 day). The apparatus components and features required for the above are presented in some detail, along with the experimental procedures. The damage processes associated with light ions are discussed and displacement rates are calculated. Recent irradiation creep results are given, demonstrating the suitability of the apparatus for high resolution experiments. Also discussed is the suitability of the ICF for making high precision thermal creep measurements.

Reiley, T.C.; Auble, R.L.; Beckers, R.M.; Bloom, E.E.; Duncan, M.G.; Saltmarsh, M.J.; Shannon, R.H.

1980-09-01

342

Prediction of Shock Pressure Histories in Cylindrical Blast Containment Chambers.  

National Technical Information Service (NTIS)

A number of containment chambers have been manufactured over the last decade for totally confined testing of high explosive charge weights ranging up to approximately 22 lbs of TNT. Typically these chambers are cylindrical, with a length to diameter ratio...

C. J. Oswald E. D. Esparza

1996-01-01

343

23. PHOTOCOPY OF PHOTOGRAPH. View west of Tropic Chamber refrigeration ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. PHOTOCOPY OF PHOTOGRAPH. View west of Tropic Chamber refrigeration equipment, ca. 1955. (Source: NRDEC). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

344

1. View southeast of Climatic Chambers Building from roof of ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. View southeast of Climatic Chambers Building from roof of Research Building. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

345

17. View northwest of Tropic Chamber refrigeration equipment, in machine ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. View northwest of Tropic Chamber refrigeration equipment, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

346

21. PHOTOCOPY OF PHOTOGRAPH. view north of Tropic Chamber, ca. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. PHOTOCOPY OF PHOTOGRAPH. view north of Tropic Chamber, ca. 1955. (Source: NRDEC). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

347

18. View north of Tropic Chamber Worthington centrifugal compressor and ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. View north of Tropic Chamber Worthington centrifugal compressor and control panel, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

348

19. View northwest of Tropic Chamber reciprocal compressors (typical), in ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. View northwest of Tropic Chamber reciprocal compressors (typical), in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

349

CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN STEEL SLABS AS THEY PROGRESS THROUGH THIS CHAMBER. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

350

Subcutaneous Fluid and Culture Chamber and Implant Technique.  

National Technical Information Service (NTIS)

The patent application discloses a subcutaneous culture chamber and implant technique for providing a priviledged site for studying infectious disease processes of microorganisms in laboratory animals. The chamber consists of a pliable polyethylene cylind...

R. J. Arko

1977-01-01

351

DESIGN, CONSTRUCTION, AND EVALUATION OF A CHAMBER FOR AEROBIOLOGY  

EPA Science Inventory

A chamber was designed and constructed for aeromicrobiology applications. An ultraviolet (UV) radiation source was incorporated to sterilize the chamber between trials. Twelve bacterial species originally isolated from air samples and obtained from the American Type Culture Colle...

352

11. Second floor, northwest chamber, south wall. Former passage to ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Second floor, northwest chamber, south wall. Former passage to southwest chamber (door blocked off on far side) on left; closet on right. - Conner Homestead, House, Epping Road (State Route 101), Exeter, Rockingham County, NH

353

30 CFR 56.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2013 CFR

...Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be flushed with a suitable solvent after the stem is pulled...

2013-07-01

354

Coupling impedance for an inhomogeneity of accelerator vacuum chamber.  

National Technical Information Service (NTIS)

Semianalytic method for calculation of coupling impedance produced by an inhomogeneity of vacuum chamber is developed. The inhomogeneity can be shaped quite generally but it has to be of the same (axial or flat) symmetry as the vacuum chamber. Substitutin...

S. S. Kurennoj S. V. Purtov

1990-01-01

355

7 CFR 58.423 - Cheese vacuumizing chamber.  

Code of Federal Regulations, 2013 CFR

...chamber. The vacuum chamber shall be satisfactorily constructed and maintained so that the product is not contaminated with rust or flaking paint. An inner liner of stainless steel or other corrosion resistant material should be...

2013-01-01

356

Polarity effect for commercially available plane-parallel ionization chambers  

Microsoft Academic Search

The polarity effect was investigated for three different commercially available plane-parallel ionization chambers: the Memorial Pipe chamber, the Victoreen\\/Nuclear Associates model 30-329 chamber manufactured by PTW, Frieburg, and the Capintec PS-033 thin-window ionization chamber. The primary study was the polarity effect versus depth below the phantom surface for 6-, 10-, 18-, and 24-MV x-ray beams, and 9- and 22-MeV electron

Bruce J. Gerbi; F. M. Khan

1987-01-01

357

Fast-burn combustion chamber design for natural gas engines  

Microsoft Academic Search

The work presented in this paper compares the performance and emissions of the UBC Squish-Jet fast-burn combustion chamber with a baseline bowl-in-piston (BIP) chamber. It was found that the increased turbulence generated in the fastburn combustion chambers resulted in 5 to 10% faster burning of the air-fuel mixture compared to a conventional BIP chamber. The faster burning was particularly noticeable

R. L. Evans; J. Blaszczyk

1998-01-01

358

Europlanet Research Infrastructure: Planetary Simulation Facilities  

NASA Astrophysics Data System (ADS)

EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the second TNA; Planetary Simulation Facilities. 11 laboratory based facilities are able to recreate the conditions found in the atmospheres and on the surfaces of planetary systems with specific emphasis on Martian, Titan and Europa analogues. The strategy has been to offer some overlap in capabilities to ensure access to the highest number of users and to allow for progressive and efficient development strategies. For example initial testing of mobility capability prior to the step wise development within planetary atmospheres that can be made progressively more hostile through the introduction of extreme temperatures, radiation, wind and dust. Europlanet Research Infrastructure Facilties: Mars atmosphere simulation chambers at VUA and OU These relatively large chambers (up to 1 x 0.5 x 0.5 m) simulate Martian atmospheric conditions and the dual cooling options at VUA allows stabilised instrument temperatures while the remainder of the sample chamber can be varied between 220K and 350K. Researchers can therefore assess analytical protocols for instruments operating on Mars; e.g. effect of pCO2, temperature and material (e.g., ± ice) on spectroscopic and laser ablation techniques while monitoring the performance of detection technologies such as CCD at low T & variable p H2O & pCO2. Titan atmosphere and surface simulation chamber at OU The chamber simulates Titan's atmospheric composition under a range of pressures and temperatures and through provision of external UV light and or electrical discharge can be used to form the well known Titan Aerosol species, which can subsequently be analysed using one of several analytical techniques (UV-Vis, FTIR and mass spectrometry). Simulated surfaces can be produced (icy surfaces down to 15K) and subjected to a variety of light and particles (electron and ion) sources. Chemical and physical changes in the surface may be explored using remote spectroscopy. Planetary Simulation chamber for low density atmospheres INTA-CAB The planetary simulation chamber-ultra-high vacuum equipment (PSC-UHV) has been designed to study planetary surfaces and low dense atmospheres, space environments or any other hypothetic environment at UHV. Total pressure ranges from 7 mbar (Martian conditions) to 5x10-9 mbar. A residual gas analyzer regulates gas compositions to ppm precision. Temperature ranges from 4K to 325K and most operations are computer controlled. Radiation levels are simulated using a deuterium UV lamp, and ionization sources. 5 KV electron and noble-gas discharge UV allows measurement of IR and UV spectra and chemical compositions are determined by mass spectroscopy. Planetary Simulation chamber for high density planetary atmospheres at INTA-CAB The facility allows experimental study of planetary environments under high pressure, and was designed to include underground, seafloor and dense atmosphere environments. Analytical capabilities include Raman spectra, physicochemical properties of materials, e.a. thermal conductivity. P-T can be controlled as independent variables to allow monitoring of the tolerance of microorganisms and the stability of materials and their phase changes. Planetary Simulation chamber for icy surfaces at INTA-CAB This chamber is being developed to the growth of ice samples to simulate the chemical and physical properties of ices found on both planetary bodies and their moons. The goal is to allow measurement of the physical properties of ice samples formed under planetary conditions to assess how rheolo

Davies, G. R.; Mason, N. J.; Green, S.; Gómez, F.; Prieto, O.; Helbert, J.; Colangeli, L.; Srama, R.; Grande, M.; Merrison, J.

2008-09-01

359

Layer Formation in Convective Magma Chambers  

NASA Astrophysics Data System (ADS)

The dynamics of a convective magma chamber is crucially influenced by the competetion between sedimentation and convective suspension of crystals. Crystal settling combined with the crystal's density contribution is a possible mechanism leading to differentiation and layer formation. Here we address the question whether crystals can remain suspended or whether they are able to dynamically form a layered structure within the convective lifetime of a magma chamber. We employ an existing numerical method that, by means of a finite volume scheme, discretizes the equations for thermally driven convection in an infinite Prandtl-number Boussinesq fluid in Cartesian geometry. We implement a newly developed settling algorithm for the numerical study of finite-sized-particle settling in a non-dilute convective suspension. Our approach considers a consistent settling velocity and the density contribution due to particle mass. The buoyancy ratio B, which is the ratio of the density variation due to crystal mass to the thermal density variation, is varied for five different Rayleigh numbers, covering a range of four orders of magnitude. We find B to be a critical parameter and its critical value to depend on the Rayleigh number. For subcritical values we observe that the presence of a crystal phase reduces convective vigor and most crystals stay suspended. When a critical buoyancy ratio is exceeded, the presence of crystals can significantly alter convective motion. For all investigated Rayleigh numbers we find a critical buoyancy ratio, above which layering can be achieved from an initially unstratified fluid. Most of the crystal mass collects in the dynamically created bottom layer, even for cases where the average settling velocity is three orders of magnitude smaller than the root mean square convective velocity. The time it takes a crystal to travel across the height of the cell with the full settling velocity in the absence of a thermal gradient defines the settling timescale. Layer formation in all observed layering cases occurs on this time scale, even though the average settling velocity is reduced by at least one order of magnitude due to hindered settling. In many cases (e.g. basaltic magma chambers) the settling time is short compared to the time that magma chambers take to solidify. We conclude that dynamical layer formation that is connected to crystal settling and the crystals' density contribution is a likely mechanism for creating layered structures within the convective lifetime of a magma chamber.

Höink, T.; Schmalzl, J.; Hansen, U.

2004-12-01

360

Replenishment of magma chambers by light inputs  

NASA Astrophysics Data System (ADS)

Magma chambers, particularly those of basaltic composition, are often replenished by an influx of magma whose density is less than that of the resident magma. This paper describes the fundamental fluid mechanics involved in the replenishment by light inputs. If ? denotes the uniform density of the resident magma and ? — ?? that of the input, the situation is described by the reduced gravity g' = g??/?, the volume flux Q, and the viscosities of the resident and input magmas ?e and ?i, respectively. The (nondimensional) Reynolds numbers, Ree = (g'Q3)1/5/?e and Rei = (g'Q3)1/5/?i and chamber geometry then completely specify the system. For sufficiently low values of the two Reynolds numbers (each less than approximately 10), the input rises as a laminar conduit. For larger values of the Reynolds numbers, the conduit may break down and exhibit either a varicose or a meander instability and entrain some resident magma. At still larger Reynolds numbers, the flow will become quite unsteady and finally turbulent. The values of the Reynolds numbers at which these transitions occur have been documented by a series of experiments with water, glycerine, and corn syrup. If the input rises as a turbulent plume, significant entrainment of the resident magma can take place. The final spatial distribution of the mixed magma depends on the geometry of the chamber. If the chamber is much wider than it is high, the mixed magma forms a compositionally stratified region between the roof and a sharp front above uncontaminated magma. In the other geometrical extreme, the input magma is mixed with almost all of the resident magma. If the density of the resident magma is already stratified, the input plume may penetrate only part way into the chamber, even though its initial density is less than that of the lowest density resident magma. The plume will then intrude horizontally and form a hybrid layer at an intermediate depth. This provides a mechanism for preventing even primitive basaltic magmas of minimum density from erupting at the surface. By conducting an experiment using aqueous solutions, we show that entrainment can lead to crystallization of the magma in the input plume by making it locally supersaturated. All these effects are discussed and illustrated by photographs of laboratory experiments.

Huppert, Herbert E.; Sparks, R. Stephen J.; Whitehead, John A.; Hallworth, Mark A.

1986-05-01

361

Intercomparison of oxygenated volatile organic (OVOC) measurements at the SAPHIR atmosphere simulation chamber  

NASA Astrophysics Data System (ADS)

This paper presents the first large scale in-situ intercomparison of oxygenated volatile organic compound (OVOC) measurements. The intercomparison was performed blind with sixteen analytical instruments challenged with measuring atmospherically relevant OVOC species and was conducted at the large (300 m3) simulation chamber, SAPHIR, in Jülich, Germany. The instruments, representing a wide variety of techniques, were challenged with different mixing ratios of OVOCs plus toluene (14 species, C1 to C7) and ozone and water in the approximate range 10-0.6 ppbV. Data will be presented for the entire 1 week study. The SAPHIR chamber proved to be an excellent facility for conducting this experiment. Measurements from individual instruments were compared to mixing ratios calculated from the chamber volume and the known amount of OVOC injected into the chamber. Most instruments and species compared to within factor of two with the calculated values. However, a number of instruments compared much better than this. Some species appeared to be easier to measure than others. For example, acetone compared very well whereas others, such as benzaldehyde, proved to be more difficult.

Apel, E. C.; Koppmann, R.; Brauers, T.

2006-12-01

362

Inertial Fusion Energy Development: What is Needed and What will be Learned at the National Ignition Facility  

Microsoft Academic Search

Successful development of inertial fusion energy (IFE) requires that many technical issues be resolved. Separability of drivers, targets, chambers and other IFE power plant subsystems allows resolution of many of these issues in off-line facilities and programs. Periodically, major integrated facilities give a snapshot of the rate of progress toward the ultimate solutions. The National Ignition Facility (NIF) and Laser

Hogan

1999-01-01

363

Inertial fusion energy development: what is needed and what will be learned at the National Ignition Facility  

Microsoft Academic Search

Successful development of inertial fusion energy (IFE) requires that many technical issues be resolved. Separability of drivers, targets, chambers, and other IFE power plant subsystems allows resolution of many of these issues in 'off-line' facilities and programs. Periodically, major 'integrated' facilities give a snapshot of the rate of progress toward the ultimate solutions. The National Ignition Facility (NIF) and Laser

William J. Hogan

2000-01-01

364

Comparison of ion chamber and TLD dosimetry in mammography  

Microsoft Academic Search

An ionization chamber method has been developed to measure exposure vs depth in a uniform BR 12 ''average breast'' phantom. It employs a Memorial mammography chamber for exit exposure measurements; resulting data is then corrected for backscatter as well as for the exceptionally thin window of this chamber. A careful comparison has then been made with relative exposure vs depth

Leonard Stanton; J. L. Day; S. D. Brattelli; D. A. Lightfoot; M. A. Vince; R. E. Stanton

1981-01-01

365

Drift Chamber with Multiwire Signal Element and Large Drift GAP.  

National Technical Information Service (NTIS)

A drift chamber with a multiwire signal element is described. The chamber can simultaneously measure particle track and determine left-right ambiguity. The operational characteristics of the chamber with a drift gap of 25 cm and wire length of 20 cm, work...

N. I. Bozhko A. A. Borisov A. S. Vovenko V. Y. Glebov A. I. Mukhin

1977-01-01

366

Flexible and telescopic vacuum chambers for the APS bunch compressor  

Microsoft Academic Search

The Advanced Photon Source (APS) bunch compressor was built with the goal of producing electron bunches with high peak current. Vacuum chamber liners were designed to, reduce the interaction of the electron beam with the surrounding chamber walls. The goal was to have the field of the beam encountering chamber walls that are smooth having diametrical changes that are well

D. R. Walters; L. H. Morrison

2001-01-01

367

Calcifications of the pulp chamber: prevalence and implicated factors.  

PubMed

The objectives of this study were to describe the prevalence of pulp chamber calcifications in a sample of Turkish dental patients and to report associations between presence of pulp chamber calcifications and dental status, gender, age, and cardiovascular diseases (CVDs). Data were collected through radiographic examination of periapical and bitewing radiographs of 15,326 teeth from 536 dental patients, comprising 270 male and 266 female patients aged between 13 and 65 years. Definite radiopaque focuses inside the radiolucent pulp chamber were defined as pulp chamber calcifications. When the pulp chamber was completely radiolucent, that tooth was scored as tooth without pulp chamber calcification. The dental status was scored as intact, carious, restored, or restored + carious. Pulp chamber calcifications were identified in 204 (38%) patients examined. Of the 15,326 teeth, 747 (4.8%) had pulp chamber calcifications. Gender and dental status were found to be correlated with the presence of pulp chamber calcifications. The high prevalence of pulp chamber calcifications in carious, restored, and restored + carious teeth support the view that the occurrence of pulp chamber calcifications can be a response to long-standing irritants. However, to report any associations between occurrence of pulp chamber calcifications and different dental or clinical status, further studies are still needed. PMID:18665398

Sener, Sevgi; Cobankara, Funda Kont; Akgünlü, Faruk

2008-07-30

368

Evaluation of the operational characteristics of a CT ionization chamber  

Microsoft Academic Search

The most common ionization chamber used in computed tomography dosimetry is the “pencil ionization chamber”. It is a special cylindrical dosimeter developed for attending computed tomography beams particularities. In this study, a Victoreen pencil ionization chamber was submitted to a set of tests for a detailed evaluation of its operational characteristics. Such as many kinds of detectors, especially field instruments,

Ana F. Maia; Linda V. E. Caldas

2006-01-01

369

Development of a guarded liquid ionization chamber for clinical dosimetry  

Microsoft Academic Search

Liquid ionization chambers are considered superior to air-filled chambers in terms of size, energy dependence and perturbation effects. We constructed and tested a liquid ionization chamber for clinical dosimetry, the GLIC-03, with a sensitive volume of approximately 2 mm3. We also examined two methods to correct for general ion recombination in pulsed photon beams: that of Johansson et al, which

K. J. Stewart; A. Elliott; J. P. Seuntjens

2007-01-01

370

Validation of reliability of fire extinguishers for medical pressure chambers  

Microsoft Academic Search

During a fire in a medical pressure chamber when operated in the regular mode it is impossible to evacuate people, and the only way to save human lives is by extinguishing the fire. The level of reliability of fire extinguishers intended for pressure chamber is examined. In case of fire, the life of people in the chamber depends entirely on

G. K. Kharisov; N. F. Bubyr

1985-01-01

371

X-ray detector with compensating secondary chamber  

Microsoft Academic Search

The present invention relates to an X-ray detector adapted to detect rays having passed through an object or an organ. This detector comprises at least one main tight chamber containing a gas ionizable by X-ray and, in this chamber, a plate for collecting the charges resulting from ionization of the gas. It comprises a secondary ionization chamber, coupled to the

R. Allemand; J. J. Gagelin; E. Tournier

1984-01-01

372

Students Learn Problem Solving with the Mars Electrostatics Chamber Project  

Microsoft Academic Search

The Mars Electrostatics Chamber is a recently developed vacuum chamber located at Kennedy Space Center (KSC) in Florida, and has been designed to provide for research and testing relative to future missions to Mars. Under the direction of one faculty member, nine students participated in the implementation and automation process for the chamber over the course of a summer. The

Randy K. Buchanan

373

Purification Characteristic Research of Carbon Dioxide in Mine Refuge Chamber  

Microsoft Academic Search

Refuge chamber is a kind of rescue equipment that protects trapped miners waiting for rescue in mine accidents. When a refuge chamber is in refuge state, carbon dioxide scrubbing is an important function of the environmental control system in chamber. In this paper, a series of experiments about the power consumption, purification efficiency, bed thickness and other factors of carbon

Jing Li; Long-zhe Jin; Sheng Wang; Shu-ci Liu; Shu Wang

2011-01-01

374

Swirl chamber arrangement for diesel engine or the like  

Microsoft Academic Search

This patent describes, in an internal combustion engine, a swirl chamber arrangement comprising: means defining a blind bore; a piston reciprocatively disposed in the bore in manner to defined a variable volume main combustion chamber, the piston having a crown; means defining a shaped recess in the crown of the piston; means defining a fixed volume pre-chamber adjacent the blind

T. Tanaka; K. Sugihara

1987-01-01

375

Criteria of choice of mode stirred reverberation chamber  

Microsoft Academic Search

The publication of RTCA DO 1601 and EN 61000-4-212 modifies the status of the mode stirred reverberation chamber. Once experimental, today they are industrial and recognized. To design a mode stirred chamber, it should take into account several criteria which influence the performances. The dimensions of the reverberation chamber and the size of the mode stirred influence the statistic uniformity

V. Keyser; J.-F. Rosnarho

2008-01-01

376

MEASUREMENT OF SOIL RESPIRATION IN SITU: CHAMBER TECHNIQUES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Chambers temporarily sealed to the soil surface are important and often the only means of measuring trace gas emissions to the atmosphere. However, such chamber measurements are not exempt from methodological problems. This review article identifies known sources of chamber-induced errors encounte...

377

Seismic Testing Facility 'Tournesol'.  

National Technical Information Service (NTIS)

The 'Tournesol' facility is a bi-axial facility intended for seismic simulation, which complements the one-axial simulation facility 'Vesuve'. A description of the facility is given. (Atomindex citation 10:445740)

C. Jeandidier P. Michon

1977-01-01

378

A radon facility at Naples University: features and first tests.  

PubMed

A radon calibration facility was developed at Naples University (Italy). It consists of an exposure chamber, a radon reference monitor and an apparatus suitable for radon circulation and air climatic control. The parameters that are possible to change and control are carrier gas, radon activity, gas pressure, temperature, and humidity. The characterization of the facility is actually underway to verify its reliability and stability with respect to various parameters of interest. PMID:19264495

Venoso, G; Pugliese, M; Roca, V; Sabbarese, C

2009-02-01

379

Space power facility for testing large space optical systems  

Microsoft Academic Search

The space power facility is located at NASA's Glenn Research Center Plum Brook Station in Sandusky, Ohio. It is the world's largest space simulation test facility with a test chamber that is 30.5m (100ft) in diameter by 37.2m (122ft) high. It has been used to test a variety of large space flight hardware and space systems for NASA, other government

Jerry Carek

2006-01-01

380

CIF (Consolidated Incineration Facility) offgas components test facility  

SciTech Connect

The Consolidated Incineration Facility (CIF) is planned for start-up at the Savannah River Site in 1993. The CIF has a unique offgas system design utilizing state-of-the-art technology and experience gained from other radioactive/hazardous waste incinerators. A high efficiency steam-atomized offgas scrubber with separate quench and scrubber liquid recirculation loops will be used. The Offgas Components Test Facility (OCTF), a 1:10 scale CIF offgas system, will evaluate operating performance of the proposed CIF system design. The primary objectives for the OCTF include demonstration of system operability, equipment performance evaluation, and CIF start-up support. The OCTF will also demonstrate to the public our commitment to operate the CIF in a manner that meets all environmental emission requirements. The CIF will treat solid and liquid RCRA hazardous and mixed wastes, and reduce the volume of low-level beta-gamma contaminated wastes. This facility can process 560,000 ft{sup 3}/yr of variability in physical and chemical characteristics of the waste feed, a rotary kiln with a secondary combustion chamber and wet offgas scrubbing system was selected. This design will insure maximum processing versatility. 1 fig.

Burns, D.B.

1990-11-01

381

Pump-down characteristics of outgassed clean stainless steel vacuum chamber and surface analysis of the chamber wall  

Microsoft Academic Search

In order to investigate pump-down characteristics of extremely high vacuum, a vacuum chamber made by clean 316L stainless steel treated by both electropolishing and outgassing at 800 °C was prepared. This chamber was evacuated by a cryosorption pump. The evacuation time to achieve the extremely high vacuum was shorter than that of an Al alloy chamber with the same size

Y Hirohata; A Mutoh; T Hino; T Yamashina; T Kikuchi; N Ohsako

1996-01-01

382

Plant growth chamber based on space proven controlled environment technology  

NASA Astrophysics Data System (ADS)

Quantum Devices, Inc., in conjunction with Percival Scientific, Inc., and the Wisconsin Center for Space Automation and Robotics (WCSAR) have developed a controlled environment plant growth chamber for terrestrial agricultural and scientific applications. This chamber incorporates controlled environment technology used in the WCSAR ASTROCULTURE™ flight unit for conducting plant research on the Space Shuttle. The new chamber, termed CERES 2010, features air humidity, temperature, and carbon dioxide control, an atmospheric contaminant removal unit, an LED lighting system, and a water and nutrient delivery system. The advanced environment control technology used in this chamber will increase the reliability and repeatability of environmental physiology data derived from plant experiments conducted in this chamber.

Ignatius, Ronald W.; Ignatius, Matt H.; Imberti, Henry J.

1997-01-01

383

Confinement of ignition and yield on the National Ignition Facility  

SciTech Connect

The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented.

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

1996-06-14

384

Basic design concept of Closed Ecology Experiment Facilities  

Microsoft Academic Search

In order to study the relationship between the physiological metabolism of living things and the environmental factors such as the atmospheric contents and so on within the closed ecosystem, Closed Ecology Experiment Facilities (CEEF) were designed and now under construction based on the following concepts: 1.(1) Individual sealed chambers (called modules) for the plant cultivation, animal breeding, human habitation and

Keiji Nitta

1999-01-01

385

Software for goniometer control in the Triple Ion Implantation Facility  

SciTech Connect

A computer program is described tat controls the goniometer employed in the ion scattering chamber of the Triple Ion Implantation Facility (TIF) in the Metals and Ceramics Division at Oak Ridge National Laboratory. Details of goniometer operation and its incorporation into the ion scattering setup specific to the TIF are also discussed.

Allen, W.R.

1994-02-01

386

Radiation Hazard Test Facilities at the Denver Research Center.  

National Technical Information Service (NTIS)

The Bureau of Mines has developed test facilities for use in a research program that deals with radiation hazards in mining. This report describes the radon test chamber located at the Denver Research Center and the Twilight experimental mine located near...

R. F. Droullard T. H. Davis E. E. Smith R. F. Holub

1984-01-01

387

A Freon-filled bubble chamber for neutron detection in inertial confinement fusion experiments  

SciTech Connect

Neutron imaging is one of the main methods used in inertial confinement fusion experiments to measure the core symmetry of target implosions. Previous studies have shown that bubble chambers have the potential to obtain higher resolution images of the targets for a shorter source-to-target distance than typical scintillator arrays. A bubble chamber for neutron imaging with Freon 115 as the active medium was designed and built for the OMEGA laser system. Bubbles resulting from spontaneous nucleation were recorded. Bubbles resulting from neutron-Freon interactions were observed at neutron yields of 10{sup 13} emitted from deuterium-tritium target implosions on OMEGA. The measured column bubble density was too low for neutron imaging on OMEGA but agreed with the model of bubble formation. The recorded data suggest that neutron bubble detectors are a promising technology for the higher neutron yields expected at National Ignition Facility.

Ghilea, M. C.; Meyerhofer, D. D.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2011-03-15

388

Extreme high-rate capable timing resistive plate chambers with ceramic electrodes  

NASA Astrophysics Data System (ADS)

The future Compressed Baryonic Matter experiment to be built at the Facility for Antiproton and Ion Research in Darmstadt, Germany, will create the highest particle densities ever created in a laboratory. One of its components, the Time-of-Flight Wall, will be comprised of Resistive Plate Chambers. The high particle fluxes expected at the most inner region, close to the beam pipe, have led to the research of new low-resistive materials to be used as electrodes. Si3N4/SiC composites are a very good candidate for this function. Their bulk resistivity, in the order of 109-1010 ? cm, allows for increased rate capabilities up to 106 s-1 cm-2. In this report, the properties of these new materials will be discussed. Also, the performance of resistive plate chambers with ceramic electrodes under irradiation in electron and proton beams will be presented.

Laso Garcia, A.; Kaspar, M.; Kämpfer, B.; Kotte, R.; Naumann, L.; Peschke, R.; Stach, D.; Wendisch, C.; Wüstenfeld, J.

2012-10-01

389

A Freon-filled bubble chamber for neutron detection in inertial confinement fusion experiments.  

PubMed

Neutron imaging is one of the main methods used in inertial confinement fusion experiments to measure the core symmetry of target implosions. Previous studies have shown that bubble chambers have the potential to obtain higher resolution images of the targets for a shorter source-to-target distance than typical scintillator arrays. A bubble chamber for neutron imaging with Freon 115 as the active medium was designed and built for the OMEGA laser system. Bubbles resulting from spontaneous nucleation were recorded. Bubbles resulting from neutron-Freon interactions were observed at neutron yields of 10(13) emitted from deuterium-tritium target implosions on OMEGA. The measured column bubble density was too low for neutron imaging on OMEGA but agreed with the model of bubble formation. The recorded data suggest that neutron bubble detectors are a promising technology for the higher neutron yields expected at National Ignition Facility. PMID:21456730

Ghilea, M C; Meyerhofer, D D; Sangster, T C

2011-03-01

390

A European Mars Simulation Wind Tunnel Facility  

NASA Astrophysics Data System (ADS)

We present details of a recently completed European simulation wind tunnel facility which is capable of re-creating the environmental conditions at the surface of Mars, this new addition complements several other large scale simulation facilities at Aarhus University in Denmark. It will be used for the multi-disciplinary scientific study of aerosol formation and transport (on Mars and earth), granular electrification, magnetic properties, erosion, cohesion/adhesion, water transport, UV induced mineralogy, bacterial survival and many others. It will be accessible to international collaborators and space agencies for instrument testing, calibration and qualification. It has been financed by the European space agency (ESA) as well as the Aarhus University Science Faculty and the Villum Kahn Rasmussen fund. The facility consists of a 50m3 environmental chamber capable of low pressure operation (0.02-1000mbar) and cryogenic temperatures (-130°C up to +60°C). This chamber houses a re-circulating wind tunnel able to generate wind speeds up to 25m/s and an automated dust injection system has been developed to produce suspended particulates (aerosols). It employs a unique LED based optical illumination system (solar simulator) and an advanced network based control system. Laser based optoelectronic instrumentation is used to quantify and monitor dust suspension and deposition. This involves a commercial Laser Doppler Anemometer and specially developed instrument prototypes constructed at Aarhus University. Photograph of the new (European) Environmental Wind Tunnel Facility.

Merrison, J. P.; Gunnlaugsson, H. P.; Knak-Jensen, S.; Per, N.

2010-12-01

391

A new ring-shaped graphite monitor ionization chamber  

NASA Astrophysics Data System (ADS)

A ring-shaped monitor ionization chamber was developed at the Instituto de Pesquisas Energéticas e Nucleares. This ionization chamber presents an entrance window of aluminized polyester foil. The guard ring and collecting electrode are made of graphite coated Lucite plates. The main difference between this new ionization chamber and commercial monitor chambers is its ring-shaped design. The new monitor chamber has a central hole, allowing the passage of the direct radiation beam without attenuation; only the penumbra radiation is measured by the sensitive volume. This kind of ionization chamber design has already been tested, but using aluminium electrodes. By changing the electrode material from aluminium to a graphite coating, an improvement in the chamber response stability was expected. The pre-operational tests, as saturation curve, recombination loss and polarity effect showed satisfactory results. The repeatability and the long-term stability tests were also evaluated, showing good agreement with international recommendations.

Yoshizumi, M. T.; Caldas, L. V. E.

2010-07-01

392

Development of neutron chambers with improved electrode design  

NASA Astrophysics Data System (ADS)

A boron-lined neutron chamber has been developed with improved electrode design. The use of suitably machined PEEK spacers at the ends of the electrodes resulted in better performance of the ion chamber. The performance of the ion chamber was compared with a similar detector developed earlier with alumina discs. Neutron sensitivity tests on both types of chambers at Apsara Thermal Column chamber showed a sharper knee in the case of the chamber with PEEK spacers due to well-defined volume and elimination of edge and fringe effects. Tests with a calibrated 60Co Teletherapy source at gamma intensity levels ranging from 900 to 3000R/h showed an average gamma compensation factor of 3.8%. The corresponding value for chambers with the alumina discs was 11.5%. A plot of the compensation factor as a function of gamma flux, showed a much more pronounced variation in the gamma compensation factor in the earlier design using alumina discs.

Alex, Mary; Prasad, D. N.; Prasad, K. R.; Kataria, S. K.

2004-07-01

393

A new combustion chamber for fast-burn applications  

SciTech Connect

A new combustion chamber design is proposed in which it is possible to control the scale and intensity of turbulence generated just prior to ignition. A single cylinder engine has been fitted with the new chamber, and measurements of the turbulence field with a hot-wire anemometer are presented. The chamber design has been compared to a conventional bowl-in-piston design under both motoring and fired operation. Hot-wire measurements showed an increase in turbulence intensity of 50% and a reduction in the length scale of turbulence compared to the conventional chamber. Cylinder pressure measurements indicated that the mass-burn rate is increased with the new chamber, particularly during the early stage of combustion. During operation at 1140 rpm with the new chamber, peak cylinder pressure was 4% higher and occurred 3/sup 0/ earlier than for the conventional chamber.

Evans, R.L.; Cameron, C.

1986-01-01

394

Posterior chamber intraocular lens dislocations and malpositions.  

PubMed

Decentration and malposition of posterior chamber intraocular lenses (PC IOL) accounts for one of the remaining and unresolved conditions associated with the implantation of these lenses. This condition assumes importance since in approximately 50% of cases where a PC IOL is removed there is an aspect of improper positioning. The common types of malpositions are: pupil capture; sunset syndrome; sunrise syndrome; horizontal decentration; and the windshield wiper syndrome. This paper will explore the causes and management of these conditions and discuss the virtues of capsular bag implantation. PMID:2679812

Obstbaum, S A; To, K

1989-08-01

395

Maintenance of condenser-ion chamber calibration.  

PubMed

Readings made with condenser-ionization chamber systems are frequently suspect because significant changes in calibration can occur without being evident in the normal use of the instruments. These changes can be traced to physical causes that alter the voltage sensitivity of electrical capacitance. Thus, measurement of these electrical parameters will indicate whether or not a change in calibration has occurred. Formulas are presented of calculating such changes and determining which parameter is responsible. Good agreement was obtained between the results of calculations with these formulas and the results of radiation measurements made with a Victoreen Condenser R-Meter after several components had been deliberately maladjusted. PMID:1186634

Rozenfeld, M

396

Depth of ionization chamber in water.  

PubMed

The device developed by the authors and described here enables the user to measure the depth from the water surface to the point of measurement for a cylindrical ion chamber with a waterproof plastic cap in a water phantom, free of surface-tension error with a high precision. The device seeks vertical orientation and provides the convenience of hands-free operation. The measurement process is simple and quick with a precision of 0.1 mm. (The device is currently available as a 'water phantom depth gauge' from Nuclear Associates, Division of Victoreen Inc., Clare Place, NY, USA.) PMID:7480120

Tailor, R C; Tello, V M

1995-08-01

397

Development of a neutron time projection chamber  

NASA Astrophysics Data System (ADS)

Time projection chambers (TPCs) have unique capabilities for the detection of fast neutrons, particularly from special nuclear materials. This includes the ability to determine directional information from a single scattering and a higher efficiency compared to other point methods, such as the scatter camera. Also, neutron TPCs are sensitive to the entire 4pi range and automatically reject gamma ray events since the ionization profile from Compton scattering is vastly different from the scattering of heavier particles. The most recent progress in the neutron TPC hardware and software development will be discussed. Preliminary results will be presented, including a calibration analysis, the directional sensitivity, and the efficiency of the detector.

Omalley, Patrick; Heffner, Mike; Bowden, Nathaniel; Carosi, Gianpaolo

2009-10-01

398

Carbon copy deaths: carbon monoxide gas chamber.  

PubMed

The news media can exert a powerful influence over suicidal behaviour. It has been observed that like-minded individuals are able to preplan a group suicide method using modern communication technology in the form of websites and online chatrooms and mobile phone texting. A case of carbon monoxide (CO) poisoning is presented to illustrate the recent phenomenon of cyber suicides by suffocation from a burning barbecue (charcoal burner) in 'gas chamber' conversions. Although barbecues (BBQ) are very popular in Britain and widely available, there have been relatively few reported cases of copycat deaths from CO gas suffocation. PMID:18586213

Patel, F

2008-04-14

399

Vacuum chamber for containing particle beams  

DOEpatents

A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

Harvey, A.

1985-11-26

400

Vacuum chamber for containing particle beams  

DOEpatents

A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer, such as nickel can be coated on the inside of the pipe.

Harvey, Alexander (Los Alamos, NM)

1987-01-01

401

BMR Characterization of Antennas through the Combined TD\\/FD Approach  

Microsoft Academic Search

\\u000a Antenna characterization measurements are traditionally performed in the frequency domain (FD) through vector network analyzers\\u000a (VNAs) in anechoic chambers. Nevertheless, the expensiveness of these facilities limits the possibility of using this approach\\u000a for routine measurements. In this chapter, the strategies for the accurate evaluation of the reflection scattering parameter\\u000a (S\\u000a 11(f)) of antennas, starting from simple time domain reflectometry (TDR)

Andrea Cataldo; Egidio Benedetto; Giuseppe Cannazza

402

Final optic protection designs for ICF containment chambers  

SciTech Connect

The output from a laser-driven high-fain ICF target in the laboratory microfusion facility (LMF) target chamber could produce enough x-rays, shrapnel, and debris to severely damage the laser's final optics. If the final optics were left unprotected, the replacement and reinstallation costs for each beam would exceed $40K. Assuming the laser has 68 beams, the replacement costs for each shot could reach $2.7M. To avoid these excessive costs, we must design a reliable optics protection system. This requires that we define the hazardous environment to which the optics are exposed. The geometrical layout for the 68 beams of the 10 megajoule laser shows the final optics placed at 25 meters from the target. The final optic will be a 2--5 cm thick debris shield ($40K each) which will be placed in front of a $200K focussing lens. Each of the 68 beams will deliver 150 kJ of 0.35 ..mu..m (3..omega..) light and will consist of either a 4 /times/ 4 or a 2 /times/ 8 array of beamlets, with each beamlet aperture having dimensions of 29 cm /times/ 29cm. This produces a 3..omega.. energy density at the final optic of 12J/cm/sup 2/ average and 225-30J/cm/sup 2/peak. 8 refs., 4 figs., 1 tab.

Nilson, D.G.; Woodworth, J.G.

1988-08-23

403

NASDA life science experiment facilities for ISS  

NASA Astrophysics Data System (ADS)

National Space Development Agency of Japan (NASDA) has been developing various experiment facilities to conduct space biology researches in KIBO (JEM). The Cell Biology Experiment Facility (CBEF) and the Clean Bench (CB) are installed into JEM Life Science Rack. The Biological Experiment Units (BEU) are operated in the CBEF and the CB for many kinds of experiments on cells, tissues, plants, microorganisms, or small animals. It is possible for all researchers to use these facilities under the system of the International Announcement of Opportunity. The CBEF is a CO2 incubator to provide a controlled environment (temperature, humidity, and CO2 concentration), in which a rotating table is equipped to make variable gravity (0-2g) for reference experiments. The containers called "Canisters" can be used to install the BEU in the CBEF. The CBEF supplies power, command, sensor, and video interfaces for the BEU through the utility connectors of Canisters. The BEU is a multiuser system consisting of chambers and control segments. It is operated by pre-set programs and by commands from the ground. NASDA is currently developing three types of the BEU: the Plant Experiment Unit (PEU) for plant life cycle observations and the Cell Experiment Unit (CEU1&2) for cell culture experiments. The PEU has an automated watering system with a water sensor, an LED matrix as a light source, and a CCD camera to observe the plant growth. The CEUs have culture chambers and an automated cultural medium exchange system. Engineering models of the PEU and CEU1 have been accomplished. The preliminary design of CEU2 is in progress. The design of the BEU will be modified to meet science requirements of each experiment. The CB provides a closed aseptic work-space (Operation Chamber) with gloves for experiment operations. Samples and the BEU can be manually handled in the CB. The CB has an air lock (Disinfection Chamber) to prevent contamination, and HEPA filters to make class-100-equivalent clean air inside the Operation Chamber. Alcohol swabs and built-in ultraviolet lamps are used to sterilize instruments and insides of the CB. The phase contrast / fluorescent microscope is equipped in the Operation Chamber to support experiments. The observed image is monitored either on the CB LCD display or on the ground through a video downlink channel. Researchers on the ground can also operate the microscope with its remote control function. Flight models of the CBEF and the CB are scheduled for completion in 2002.

Tanigaki, F.; Masuda, D.; Yano, S.; Fujimoto, N.; Kamigaichi, S.

404

Adenosine 3',5'-monophosphate analogue increases the outflow facility of the  

Microsoft Academic Search

Our previous studies showed that cyclic-AMP increases the outflow facility of the eye of the rabbit. In this investigation, an analogue of cyclic- AMP, the 8-methylthio derivative, perfused into the anterior chamber of the eye of the vervet monkey, increased outflow facility twofold. This observation supports the hypothesis that cyclic- AMP mediates the action of adrenergic agents to reduce intraoctdar

ARTHUR H. NEUFELD; MARVIN L. SEARS

1975-01-01

405

Intercomparison of oxygenated volatile organic compound measurements at the SAPHIR atmosphere simulation chamber  

NASA Astrophysics Data System (ADS)

This paper presents results from the first large-scale in situ intercomparison of oxygenated volatile organic compound (OVOC) measurements. The intercomparison was conducted blind at the large (270 m3) simulation chamber, Simulation of Atmospheric Photochemistry in a Large Reaction Chamber (SAPHIR), in Jülich, Germany. Fifteen analytical instruments, representing a wide range of techniques, were challenged with measuring atmospherically relevant OVOC species and toluene (14 species, C1 to C7) in the approximate range of 0.5-10 ppbv under three different conditions: (1) OVOCs with no humidity or ozone, (2) OVOCs with humidity added (r.h. ? 50%), and (3) OVOCs with ozone (?60 ppbv) and humidity (r.h. ? 50%). The SAPHIR chamber proved to be an excellent facility for conducting this experiment. Measurements from individual instruments were compared to mixing ratios calculated from the chamber volume and the known amount of OVOC injected into the chamber. Benzaldehyde and 1-butanol, compounds with the lowest vapor pressure of those studied, presented the most overall difficulty because of a less than quantitative transfer through some of the participants' analytical systems. The performance of each individual instrument is evaluated with respect to reference values in terms of time series and correlation plots for each compound under the three measurement conditions. A few of the instruments performed very well, closely matching the reference values, and all techniques demonstrated the potential for quantitative OVOC measurements. However, this study showed that nonzero offsets are present for specific compounds in a number of instruments and overall improvements are necessary for the majority of the techniques evaluated here.

Apel, E. C.; Brauers, T.; Koppmann, R.; Bandowe, B.; BoßMeyer, J.; Holzke, C.; Tillmann, R.; Wahner, A.; Wegener, R.; Brunner, A.; Jocher, M.; Ruuskanen, T.; Spirig, C.; Steigner, D.; Steinbrecher, R.; Gomez Alvarez, E.; Müller, K.; Burrows, J. P.; Schade, G.; Solomon, S. J.; LadstäTter-WeißEnmayer, A.; Simmonds, P.; Young, D.; Hopkins, J. R.; Lewis, A. C.; Legreid, G.; Reimann, S.; Hansel, A.; Wisthaler, A.; Blake, R. S.; Ellis, A. M.; Monks, P. S.; Wyche, K. P.

2008-10-01

406

Measurements of a 1/4-scale model of a 60-kg explosives firing chamber  

SciTech Connect

In anticipation of increasingly stringent environmental regulations, Lawrence Livermore National Laboratory (LLNL) proposes to construct a 60-kg firing chamber to provide blast-effects containment for, most of its open-air, high-explosive, firing operations. Even though these operations are within current environmental limits, containment of the blast effects and hazardous debris will further drastically reduce emissions to the environment and minimize the generated hazardous waste. The major design consideration of such a chamber is its overall structural dynamic response in terms of long-term containment of all blast effects from repeated internal detonations of high explosives. Another concern is how much other portions of the facility must be hardened to ensure personnel protection in the event of an accidental detonation. To assess these concerns, a 1/4-scale replica model of the planned contained firing chamber was designed, constructed, and tested with scaled explosive charges ranging from 25 to 125% of the operational explosives limit of 60 kg. From 16 detonations of high explosives, 880 resulting strains, blast pressures, and temperatures within the model were measured. Factors of safety for dynamic yield of the firing chamber structure were calculated and compared to the design criterion of totally elastic response. The rectangular, reinforced-concrete chamber model exhibited a lightly damped vibrational response that placed the structure in alternating cycles of tension and compression. During compression, both the reinforcing steel and the concrete remained elastic. During tension, the reinforcing steel remained elastic, but the concrete elastic limit was exceeded in two areas, the center spans of the ceiling and the north wall, where elastic safety factors as low as 0.66 were obtained, thus indicating that the concrete would be expected to crack in those areas. Indeed, visual post-test inspection of those areas revealed tight cracks in the concrete.

Pastrnak, J.W.; Baker, C.F.; Simmons, L.F.

1995-01-27

407

Wire chamber radiation detector with discharge control  

DOEpatents

A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

Perez-Mendez, Victor (Berkeley, CA); Mulera, Terrence A. (Berkeley, CA)

1984-01-01

408

Operation of high rate microstrip gas chambers  

NASA Astrophysics Data System (ADS)

We describe recent measurements carried out in well controlled and reproducible conditions to help understanding the factors affecting the short- and long-term behaviour of Microstrip Gas Chambers. Special care has been taken concerning the gas purity and choice of materials used in the system and for the detectors construction. Detectors built on glasses with surface resistivity in the range 1013-1015 ?/? have shown satisfactory performance as they do not show charging-up process at high rate and stand the large doses required for the future high luminosity experiments (~10mCcm-1yr-1). Concerning the lifetime measurements, it has been observed that chambers manufactured on high-resistivity glass are far more susceptible of suffering ageing than detectors made on low resistivity, electron-conducting supports, independently of the metal used for the artwork (chromium or gold) at least in clean gas conditions. The successful operation in the laboratory of detectors manufactured on diamond-coated glass with a surface resistivity around 1015 ?/? confirms the last statement. Results from a long-term, high rate beam test are also reported.

Barr, A.; Boimska, B.; Bouclier, R.; Capeáns, M.; Dominik, W.; Manzin, G.; Million, G.; Hoch, M.; Ropelewski, L.; Sauli, F.; Sharma, A.

1997-02-01

409

A New Gas Ionization Chamber For HELIOS  

NASA Astrophysics Data System (ADS)

The HELIcal Orbit Spectrometer (HELIOS) has become an important tool in studying reactions using radioactive ion beams, and its special design has successfully alleviated problems that arise from studying reactions in inverse kinematics, such as kinematic compression. Here we introduce a new gas ionization chamber, which will significantly improve heavy recoil detection in HELIOS. On one hand, it will help eliminate background by detecting the heavy secondary recoils in coincidence with the light reaction products detected in the silicon detector array; on the other hand, our chamber can tolerate count rates of at least 100 kHz. As a result, a high detection efficiency will be achieved. This design, which functions well with beam rates above 10^5 pps, and obtains a ?Z/Z resolution better than 2%, will be presented. In addition, we will also show the first test results from this detector, which illustrate the detector's performance. In the future, this detector will be used for radioactive ion beam experiments of interest for nuclear structure and nuclear astrophysics, such as those important for X-ray burst nucleosynthesis.

Lai, Jianping

2012-10-01

410

Linking a one-dimensional reverberation chamber model with real Reverberation Chambers  

Microsoft Academic Search

Our work focuses on the study of a simple yet complete one-dimensional reverberation chamber model presented previously. The statistical properties of the fields are introduced either by varying the width or the relative dielectric constant of a perturbing lossless layer. Our aim is to show the excellent agreement between this simple model and real RCs. The field statistics in undermoded

Ramiro Serra; Flavio Canavero

2008-01-01

411

Two-dimensional ionization chamber arrays for IMRT plan verification  

SciTech Connect

In this paper we describe a concept for dosimetric treatment plan verification using two-dimensional ionization chamber arrays. Two different versions of the 2D-ARRAY (PTW-Freiburg, Germany) will be presented, a matrix of 16x16 chambers (chamber cross section 8 mmx8 mm; the distance between chamber centers, 16 mm) and a matrix of 27x27 chambers (chamber cross section 5 mmx5 mm; the distance between chamber centers is 10 mm). The two-dimensional response function of a single chamber is experimentally determined by scanning it with a slit beam. For dosimetric plan verification, the expected two-dimensional distribution of the array signals is calculated via convolution of the planned dose distribution, obtained from the treatment planning system, with the two-dimensional response function of a single chamber. By comparing the measured two-dimensional distribution of the array signals with the expected one, a distribution of deviations is obtained that can be subjected to verification criteria, such as the gamma index criterion. As an example, this verification method is discussed for one sequence of an IMRT plan. The error detection capability is demonstrated in a case study. Both versions of two-dimensional ionization chamber arrays, together with the developed treatment plan verification strategy, have been found to provide a suitable and easy-to-handle quality assurance instrument for IMRT.

Poppe, Bjoern; Blechschmidt, Arne; Djouguela, Armand; Kollhoff, Ralf; Rubach, Antje; Willborn, Kay C.; Harder, Dietrich [Klinik fuer Strahlentherapie und Internistische Onkologie, Pius-Hospital, Oldenburg, Germany, and Carl-von-Ossietzky-Universitaet Oldenburg, Oldenburg (Germany); Carl-von-Ossietzky-Universitaet Oldenburg, Oldenburg (Germany); Klinik fuer Strahlentherapie und Internistische Onkologie, Pius-Hospital, Oldenburg (Germany); Georg-August-Universitaet Goettingen, Goettingen (Germany)

2006-04-15

412

Design and characterization of a smog chamber for studying gas-phase chemical mechanisms and aerosol chemistry  

NASA Astrophysics Data System (ADS)

We describe here characterization of a new state-of-the-art smog chamber facility for studying atmospheric gas phase and aerosol chemistry. The chamber consists of a 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor suspended in a temperature-controlled enclosure equipped with two banks of black lamps as the light source. Temperature can be set in the range from -10 °C to 40 °C at accuracy of ±1 °C as measured by eight temperature sensors inside the enclosure and one just inside the reactor. Matrix air can be purified with NMHCs < 0.5 ppb, NOx/O3/carbonyls < 1 ppb and particles < 1 cmchamber are determined and included in the Master Chemical Mechanism to evaluate and model propene-NOx-air irradiation experiments. The results indicate that this new smog chamber can provide high quality data for mechanism evaluation. Results of ?-pinene dark ozonolysis experiments revealed SOA yields comparable to those from other chamber studies, and the two-product model gives a good fit for the yield data obtained in this work. Characterization experiments demonstrate that our GIG-CAS smog chamber facility can be used to provide valuable data for gas-phase mechanisms and aerosol chemistry.

Wang, X.; Liu, T.; Bernard, F.; Ding, X.; Wen, S.; Zhang, Y.; Zhang, Z.; He, Q.; Lü, S.; Chen, J.; Saunders, S.; Yu, J.

2013-08-01

413

Characterization of cylindrical ionization chambers for patient specific IMRT QA.  

PubMed

Proven conventional dosimetry techniques do not provide accuracy and precision in the measurement of inverse planned intensity modulated radiation therapy (IMRT) fields. Dynamic and step-and-shoot multileaf collimation (DMLC/SMLC) challenge current ionization chamber dosimetry practices. Ionization chamber performance in these fields is evaluated for three cylindrical chambers of varying volumes (PinPoint (PP): 0.015 cm3, IC10: 0.13 cm3, Farmer type NE2571 (FT): 0.69 cm3) in terms of measurement reproducibility, dose measurement linearity, and IMRT dose measurements. Fifty IMRT patient specific quality assurance dose measurements were performed with each chamber. DMLC measurements are compared between chambers, and to dose calculations from a commercial treatment planning system (TPS) that used a finite size pencil beam model (FSPB). Ten SMLC measurements are compared to Monte Carlo simulations available in the TPS. The three chambers demonstrated adequate measurement reproducibility characteristics for both open and DMLC fields with each chamber able to perform within 2% (2SD) for DMLC fields. Both smaller volume chambers over responded (> 5%) when irradiated with a small number of monitor units in open fields. FT and IC10 chambers demonstrated dose linearity in DMLC fields down to 10 monitor units, while dose linearity for the PP chamber broke down at 100 monitor units. The evaluation of fifty DMLC treatment plan quality assurance procedures revealed that the FT chamber measurements were closest to the FSPB calculated values (FSPB: 1.0, FT: 0.973 +/- 0.044, IC10: 0.963 +/- 0.048, PP: 0.944 +/- 0.071). Quality assurance plans calculated independently with Monte Carlo more closely matched chamber measurements (FSPB: 1.0, MC: 0.97, FT: 0.95). Measurements of absorbed dose to water in IMRT fields are highly chamber and IMRT plan dependent. PMID:19918222

Fraser, Danielle; Parker, William; Seuntjens, Jan

2009-09-30

414

A fail safe laser activated switch used as an emergency control link at the Langley Vortex Research Facility  

Microsoft Academic Search

A fail safe light activated switch was used as an emergency control link at the Langley Vortex Research Facility. In this facility aircraft models were towed through a still air test chamber by a gasoline powered vehicle which was launched from one end of a 427-meter track and attained velocities to 31 m\\/sec in the test chamber. A 5 mW

P. C. Kassel Jr.

1978-01-01

415

Observation Of Individual Particles In The Two-Proton Radioactivity With A Time Projection Chamber  

SciTech Connect

After the recent discovery of two-proton radioactivity, an important effort has been made in order to observe each emitted particle individually. Such kind of studies may result in energy and angular correlation measurements of the protons, which are required to give a precise theoretical description of this exotic decay mode. In this frame, we performed an experiment at the GANIL/SISSI/LISE3 facility, where we used a Time Projection Chamber to observe tracks of protons in the decay of {sup 45}Fe, produced in projectile fragmentation reactions.

Giovinazzo, J.; Blank, B.; Audirac, L.; Borcea, C.; Canchel, G.; Demonchy, C. E.; Hay, L.; Huikari, J.; Leblanc, S.; Matea, I.; Pedroza, J.-L.; Pibernat, J.; Serani, L. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan-Universite Bordeaux I-UMR 5797 CNRS/IN2P3 (France); Oliveira Santos, F. de; Grevy, S.; Perrot, L.; Stodel, C.; Thomas, J.-C. [Grand Accelerateur National d'Ions Lourds, CEA/DSM--CNRS/IN2P3 (France); Dossat, C. [DAPNIA, CEA Saclay (France)

2007-11-30

416

Accumulation of spatial charge in the time projection chamber of a multipurpose detector  

NASA Astrophysics Data System (ADS)

This article presents the results of a numerical simulation of the process of spatial positive charge accumulation in the Time Projection Chamber (TPC) of the multipurpose detector (MPD) at Nuclotron-based Ion Collider fAcility (NICA) at the Joint Institute for Nuclear Research (JINR). Based on the spatial distribution of the charges, the problem of calculating the potential of the electrostatic field created by these charges has been solved. The radial, angular, and axial distortions in the electron motions from the point of ionization to the readout planes are calculated.

Merts, S. P.; Razin, S. V.; Rogachevskii, O. V.

2013-01-01

417

A fast position sensitive microstrip-gas-chamber detector at high count rate operation  

NASA Astrophysics Data System (ADS)

Testing of a newly developed position sensitive high count rate microstrip gas chamber (MSGC) detector at high count rate operation has been carried out at the Dutch-Belgian x-ray scattering beamline at the European Synchrotron Radiation Facility (Grenoble, France) with a high intensity x-ray beam. The measurements show local count rate capabilities up to approx4.5 x105 counts/s/channel. Experimental data taken with this detector are also shown. These tests show that both time resolution down to 1.5 ms/frame and a reliable operation at high counting rates can be achieved.

Dolbnya, I. P.; Alberda, H.; Hartjes, F. G.; Udo, F.; Bakker, R. E.; Konijnenburg, M.; Homan, E.; Cerjak, I.; Goedtkindt, P.; Bras, W.

2002-11-01

418

A new multi-strip ionization chamber used as online beam monitor for heavy ion therapy  

NASA Astrophysics Data System (ADS)

A multi-strip ionization chamber has been built for precise and fast monitoring of the carbon beam spatial distribution at Heavy Ion Researched Facility of Lanzhou Cooling Storing Ring (HIRFL-CSR). All the detector's anode, cathode and sealed windows are made by 2?m aluminized Mylar film in order to minimize the beam lateral deflection. The sensitive area of the detector is (100×100)mm2, with the anode segmented in 100 strips, and specialized front-end electronics has been developed for simplifying the data acquisition and quick feedback of the relevant parameters to beam control system. It can complete one single beam profile in 200?s.

Xu, Zhiguo; Mao, Ruishi; Duan, Limin; She, Qianshun; Hu, Zhengguo; Li, He; Lu, Ziwei; Zhao, Qiecheng; Yang, Herun; Su, Hong; Lu, Chengui; Hu, Rongjiang; Zhang, Junwei

2013-11-01

419

Explosive components facility certification tests  

SciTech Connect

Sandia National Laboratories has recently completed construction of a new Explosive Components Facility (ECF) that will be used for the research and development of advanced explosives technology. The ECF includes nine indoor firing pads for detonating explosives and monitoring the detonations. Department of Energy requirements for certification of this facility include detonation of explosive levels up to 125 percent of the rated firing pad capacity with no visual structural degradation resulting from the explosion. The Explosives Projects and Diagnostics Department at Sandia decided to expand this certification process to include vibration and acoustic monitoring at various locations throughout the building during these explosive events. This information could then be used to help determine the best locations for noise and vibration sensitive equipment (e.g. scanning electron microscopes) used for analysis throughout the building. This facility has many unique isolation features built into the explosive chamber and laboratory areas of the building that allow normal operation of other building activities during explosive tests. This paper discusses the design of this facility and the various types of explosive testing performed by the Explosives Projects and Diagnostics Department at Sandia. However, the primary focus of the paper is directed at the vibration and acoustic data acquired during the certification process. This includes the vibration test setup and data acquisition parameters, as well as analysis methods used for generating peak acceleration levels and spectral information. Concerns over instrumentation issues such as the choice of transducers (appropriate ranges, resonant frequencies, etc.) and measurements with long cable lengths (500 feet) are also discussed.

Dorrell, L.; Johnson, D. [Sandia National Labs., Albuquerque, NM (United States)

1995-08-01

420

Radiated electromagnetic fields of actual devices measured in different test environments  

Microsoft Academic Search

Correction factors between test sites are conventionally based on the antenna pattern of a tuned 1\\/2 ? dipole. Actual devices show diverse antenna patterns and correlation between results obtained at different test sites fails. This is shown in this paper using an Open Area Test Site, a Semi-Anechoic Chamber, a Full Anechoic Chamber and a Reverberating Intrinsic Reverberation Chamber for

Frank Leferink; Gerben Hilverda; Dick Groot Boerle; Wim van Etten

2003-01-01

421

Overview of the National Ignition Facility.  

PubMed

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. The NIF is a 192-beam, Nd-glass laser facility that is capable of producing 1.8 MJ, 500 TW of ultraviolet light, and over 50 times more energetic than other existing ICF facilities. The NIF construction began in 1997, and the facility, which was completed in 2009, is now fully operational. The facility is capable of firing up to 192 laser beams onto a target placed at the center of a 10-m-diameter spherical target chamber. Experiments involving the use of tritium have been underway for some time. These experiments present radiological issues: prompt neutron/gamma radiation, neutron activation, fission product generation, and decay radiation. This paper provides an introduction to the NIF facility and its operation, describes plans for the experimental program, and discusses radiological issues associated with the NIF's operations. PMID:23629059

Brereton, Sandra

2013-06-01

422

NASA Glenn Research Center Creek Road Complex—Cryogenic Testing Facilities  

NASA Astrophysics Data System (ADS)

Due to expansion at neighboring Cleveland Hopkins Airport, several NASA Glenn Research Center (GRC) facilities have been relocated to the Creek Road Complex. The complex consists of the Small Scale Multi-purpose Research Facility (SMiRF), Cryogenic Components Lab Cell 7 (CCL-7), and a shop building. The facilities have been updated and include state-of-the art technology. SMiRF is a liquid hydrogen/liquid nitrogen (LH2/LN2) test facility used to conduct research in a 7400 L vacuum chamber. The chamber simulates space environment and launch vehicle ascent profile. SMiRF handles 5680 L of LH2. CCL is a LH2/LN2 facility to perform small scale proof of concept tests for components and processes. It handles 1130 L of liquid hydrogen. Both facilities handle cryogens at sub-atmospheric pressures.

Jurns, John M.; Kudlac, Maureen T.

2006-02-01

423

New details on magma chamber beneath Soufrière Hills volcano  

NASA Astrophysics Data System (ADS)

Assessing volcano hazard and forecasting eruptions require knowledge of the geometry and properties of a volcano's magma chamber. However, there are few high-resolution seismic imagery studies of magma chambers. Paulatto et al. used seismic tomography along with numerical models of magma chamber growth to get a better picture of the magma chamber beneath the active Soufrière Hills volcano on the island of Montserrat. Their approach reveals details of the magma system that have not been shown in previous studies. The authors' analysis shows that the magma chamber contains about 13 cubic kilometers of magma, with more than 30% melt faction between about 5.5- and 7.5-kilometer depth. The researchers suggest that the magma chamber could have formed through sill intrusion over several thousand years. (Geochemistry, Geophysics, Geosystems (G3), doi:10.1029/2011GC003892, 2012)

Balcerak, Ernie

2012-02-01

424

Measurement and Compensation of BPM Chamber Motion in HLS  

SciTech Connect

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20{mu}m without the compensation of BPM chamber motion in the runtime.

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G. [NSRL, School of Nuclear Science and Technology, University of Science and Technology of China Hefei, Anhui230029 (China)

2010-06-23

425

Measurement and Compensation of BPM Chamber Motion in HLS  

NASA Astrophysics Data System (ADS)

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20?m without the compensation of BPM chamber motion in the runtime.

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

2010-06-01

426

Posterior chamber pseudophakes in glaucoma patients.  

PubMed

In the past, glaucoma has been considered a relative contraindication to the use of an intraocular lens (IOL) in a patient undergoing cataract extraction. In this study, we examined postoperative intraocular pressure (IOP) control for three months postoperatively in 46 eyes with glaucoma undergoing cataract extraction with implantation of a posterior chamber IOL. Twenty-six eyes or 56.5% could be classified as having improved IOP control three months postoperatively. At the same time, 19 eyes or 41.3% demonstrated the same IOP control after lens implantation. Thus, 45 of the total of 46 eyes had as good or better postoperative IOP control. Of the 46 eyes, 100% required preoperative glaucoma medication, while postoperatively only 41% required medication. PMID:3960473

McMahan, L B; Monica, M L; Zimmerman, T J

1986-03-01

427

Nuclear Fission Investigation with Twin Ionization Chamber  

NASA Astrophysics Data System (ADS)

The purpose of the present paper was to report the recent results, obtained in development of digital pulse processing mathematics for prompt fission neutron (PFN) investigation using twin ionization chamber (TIC) along with fast neutron time-of-flight detector (ND). Due to well known ambiguities in literature (see refs. [4, 6, 9 and 11]), concerning a pulse induction on TIC electrodes by FF ionization, we first presented detailed mathematical analysis of fission fragment (FF) signal formation on TIC anode. The analysis was done using Ramo-Shockley theorem, which gives relation between charged particle motion between TIC electrodes and so called weighting potential. Weighting potential was calculated by direct numerical solution of Laplace equation (neglecting space charge) for the TIC geometry and ionization, caused by FF. Formulae for grid inefficiency (GI) correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and discussed.

Zeynalova, O.; Zeynalov, Sh.; Nazarenko, M.; Hambsch, F.-J.; Oberstedt, S.

2011-11-01

428

Nuclear Fission Investigation with Twin Ionization Chamber  

SciTech Connect

The purpose of the present paper was to report the recent results, obtained in development of digital pulse processing mathematics for prompt fission neutron (PFN) investigation using twin ionization chamber (TIC) along with fast neutron time-of-flight detector (ND). Due to well known ambiguities in literature (see refs. [4, 6, 9 and 11]), concerning a pulse induction on TIC electrodes by FF ionization, we first presented detailed mathematical analysis of fission fragment (FF) signal formation on TIC anode. The analysis was done using Ramo-Shockley theorem, which gives relation between charged particle motion between TIC electrodes and so called weighting potential. Weighting potential was calculated by direct numerical solution of Laplace equation (neglecting space charge) for the TIC geometry and ionization, caused by FF. Formulae for grid inefficiency (GI) correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and discussed.

Zeynalova, O.; Zeynalov, Sh. [JINR-Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Nazarenko, M. [Moscow State Institute of Radioengineering and Automation, 78 Vernadski Avenue, 119454 Moscow (Russian Federation); Hambsch, F.-J.; Oberstedt, S. [EC-JRC Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel (Belgium)

2011-11-29

429

Development of an optical digital ionization chamber  

SciTech Connect

We are developing a new device for optically detecting and imaging the track of a charged particle in a gas. The electrons in the particle track are made to oscillate rapidly by the application of an external, short-duration, high-voltage, RF electric field. The excited electrons produce additional ionization and electronic excitation of the gas molecules in their immediate vicinity, leading to copious light emission (fluorescence) from the selected gas, allowing the location of the electrons along the track to be determined. Two digital cameras simultaneously scan the emitted light across two perpendicular planes outside the chamber containing gas. The information thus obtained for a given track can be used to infer relevant quantities for microdosimetry and dosimetry, e.g., energy deposited, LET, and track structure in the gas. The design of such a device now being constructed and methods of obtaining the dosimetric data from the digital output will be described. 4 refs., 4 figs.

Turner, J.E.; Hunter, S.R.; Hamm, R.N.; Wright, H.A.; Hurst, G.S.; Gibson, W.A.

1988-01-01

430

Dual-chamber pacing in hypertrophic cardiomyopathy.  

PubMed

This review focuses on recent developments in the field of pacing in hypertrophic cardiomyopathy (HCM). Regarding mechanisms of action, recent data indicates that pacing acts by inducing dysynchronous left ventricular activation, thus reducing contractility and increasing end-systolic volume. Following several positive uncontrolled studies, three randomized crossover trials, with a total of approximately 140 patients, have now confirmed that gradients are on average halved with pacing but the reduction in symptoms has been modest and maximum exercise capacity has not been improved. These studies have identified a placebo effect from pacemaker implantation in HCM and have questioned the efficacy of pacing as a symptomatic therapy for HCM. There is probably a subgroup of patients with HCM who respond to permanent dual-chamber pacing but their precise identification is not yet clear. Permanent pacing should continue to be considered as one option in the management of the patient with drug refractory, symptomatic obstructive HCM. PMID:10980887

Gilligan, D M

2000-03-01

431

Information revolution: William Chambers, the publishing pioneer.  

PubMed

With the arrival of steam power and new machinery in the 19th century, the production of printed media was transformed for the first time since the emergence of the printing press more than 300 years earlier. Yet until the 1850s, most publishers remained content with traditional methods, which enabled them to make profits from a small but affluent circle of readers. This article (part of the Science in the Industrial Revolution series) will show how William Chambers (1800-1883) was one of the first to make full use of the new technologies. He was driven by a determination to reach readers of all social classes, to produce a genuinely cheap instructive publication and to overcome the challenges of reaching a national market from his base in Edinburgh. PMID:17112590

Fyfe, Aileen

2006-11-16

432

Plasma arc heated secondary combustion chamber  

SciTech Connect

This paper describes a secondary combustion chamber (SCC) for hazardous waste treatment systems that uses a plasma arc torch as the heat source. Developed under a cooperative research and development agreement (CRADA) between Retech, Inc. and Lawrence Livermore National Laboratory (LLNL), the unit is intended primarily to handle the off-gas from a Plasma Arc Centrifugal Treatment (PACT) system. ft is designed to heat the effluent gas which may contain volatile organic compounds, and maintain the gas temperature above 1000 C for two seconds or more. The benefits of using a plasma arc gas heater are described in comparison to a conventional fossil fuel heated SCC. Thermal design considerations are discussed. Analysis and experimental results are presented to show the effectiveness in destroying hazardous compounds and reducing the total volume of gaseous emissions.

Haun, R.; Paulson, B.; Schlienger, M. [Retech, Inc. (United States); Goerz, D.; Kerns, J.; Vernazza, J. [Lawrence Livermore National Lab., CA (United States)

1995-02-01

433

Neutron sensitivity of thin gap chambers  

NASA Astrophysics Data System (ADS)

Thin gap chambers (TGC) will be used for triggering forward muons in the ATLAS detector for the LHC at CERN. A large amount of neutron background is foreseen in the ATLAS experiment. This paper describes the measurements of the neutron sensitivities (detection efficiencies) of the TGCs. The sensitivities of both small and real size TGCs to 2.5 and 14MeV mono-energetic neutrons were measured. For a small size TGC, sensitivities of 0.032% and 0.10% were measured to 2.5 and 14MeV neutrons, respectively, whereas for a real size TGC, sensitivities of 0.048% and 0.13% were measured. These measured values were in reasonably good agreement with the simulations based on the Geant4.

Nanjo, H.; Bando, T.; Hasuko, K.; Ishino, M.; Kobayashi, T.; Takemoto, T.; Tsuno, S.; Ye, B.

2005-05-01

434

Emulsion chamber observations of primary electrons  

NASA Astrophysics Data System (ADS)

Recent observations of high-energy primary electrons, using emulsion chambers exposed by balloon (Nishimura et al., 1980), have been extended to a net exposure factor of about 7 sq m-sr-day. This is more than an order of magnitude greater than that obtained by other experimental techniques. The propagation of electrons is based on a model, similar to the leaky box model, which makes it possible to obtain statistically significant measurements of the electron spectrum in the TeV range. The data indicate a depression of the spectrum beyond approximately 1 TeV; this depression of high energy electrons above 1 TeV reflects the acceleration mechanism at the source.

Nishimura, J.; Fujii, M.; Taira, T.; Aizu, E.; Nomura, Y.; Kobayashi, T.; Niu, K.; Nishio, A.; Golden, R. L.; Koss, T. A.

435

Plant exposure laboratory and chambers. Volume 1  

SciTech Connect

The research is to learn the factors that control plant uptake, translocation, and metabolism of anthropogenic organic chemicals. Understanding these processes is essential to predict food contamination and environmental damage from various agricultural and industrial pollutants. Contamination of plants is only one component, but since plants are the fulcrum upon which all nourishment systems depend, understanding the ways they become contaminated is critical to prudent production, transportation, and use of organic chemicals. These efforts to identify the controlling mechanisms of these phenomena require an understanding of the physiological parameters of the plants during uptake and translocation of the extraneous chemicals. Since the chemicals of interest are toxic and studies generally include /sup 14/C as a label for monitoring chemical kinetics, containment is an important criterion. The paper describes the laboratory and support system, the exposure chambers, the computer system, and the plant hydroponic nursery built to accomplish this research.

McFarlane, C.; Pfleeger, T.

1986-01-01

436

Microstrip gas chambers on thin plastic supports  

SciTech Connect

In this paper, the authors describe the development of microstrip gas chambers manufactured on thin-foil plastic supports. Gains up to 10[sup 4] and energy resolutions around 20% fwhm have been obtained for low rate 5.9 keV x-rays. A space-charge dominated gain drop appears only at very high rates, close to 10[sup 6] s[sup [minus] 1] [center dot] mm[sup [minus]2]. The measurements show however long-term time-dependent modifications (charging up), particularly for high resistivity supports; nevertheless, the results are very encouraging and further developments may lead to the development of a new family of light, flexible detectors with high resolution.

Bouclier, R.; Florent, J.J; Gaudaen, J.; Million, G.; Ropelewski, L.; Sauli, F. (European Organization for Nuclear Research, Geneva (Switzerland))

1992-08-01

437

Influence of high rotational speeds on heat transfer and oil film thickness in aero-engine bearing chambers  

NASA Astrophysics Data System (ADS)

Increasing the thermal loading of bearing chambers in modern aero-engines requires advanced techniques for the determination of heat transfer characteristics. In the present study, film thickness and heat transfer measurements have been carried out for the complex two-phase oil/air flow in bearing chambers. In order to ensure real engine conditions, a new test facility has been built up, designed for rotational speeds up to n = 16,000 rpm and maximum flow temperatures of T(sub max) = 473 K. Sealing air and lubrication oil flow can be varied nearly in the whole range of aero-engine applications. Special interest is directed toward the development of an ultrasonic oil film thickness measuring technique, which can be used without any reaction on the flow inside the chamber. The determination of local heat transfer at the bearing chamber housing is based on a well-known temperature gradient method using surface temperature measurements and a finite element code to determine temperature distributions within the bearing chamber housing. The influence of high rotational speed on the local heat transfer and the oil film thickness is discussed.

Wittig, S.; Glahn, A.; Himmelsbach, J.

1994-04-01

438

IFE chamber dry wall materials response to pulsed X-rays and ions at power-plant level fluences  

Microsoft Academic Search

We have begun a collaborative investigation of the response of candidate first-wall inertial fusion energy (IFE) reactor chamber drywall materials to X-rays on the Z facility, and to ions on RHEPP-1, both located at Sandia National Laboratories. Dose levels are comparable to those anticipated in future direct-drive reactors. Due to the 5–10 Hz repetition rate expected in such reactors, per-pulse

T. J. Renk; C. L. Olson; T. J. Tanaka; M. A. Ulrickson; G. A. Rochau; R. R. Peterson; I. E. Golovkin; M. O. Thompson; T. R. Knowles; A. R. Raffray; M. S. Tillack

2003-01-01

439

Modeling of Solid Waste Flow and Mixing on the Traveling Grate of a Waste-to- energy Combustion Chamber  

Microsoft Academic Search

Mixing of the highly non-homogeneous municipal solid wastes (MSW) on the traveling grate of mass-burn combustion chambers assists the combustion process in waste-to-energy (WTE) facilities. A matrix-based Markov chain model was developed to simulate particle flow and mixing as the solid waste particles travel over a reverse acting Martin grate. The model was used to project the pathway of a

MASATO NAKAMURA; N. J. THEMELIS

440

Threshold dependence of strip clusters for the forward region resistive plate chamber of the CMS\\/LHC experiment  

Microsoft Academic Search

Strip clusters of muons and background hits induced by gamma rays and spurious pulses are analyzed for the Forward Region Resistive Plate Chamber of the CMS\\/LHC. In order to perform the analysis, a real size RE2\\/1 prototype RPC manufactured with the final baseline design of the Forward Region RPCs was tested at the Gamma Irradiation Facility of CERN. Strip cluster

S. H Ahn; S. Y Bahk; E. J Choi; B. Hong; S. J Hong; S. R Jung; T. J Kim; Y. J Kim; Y. U Kim; D. G Koo; H. W Lee; K. S Lee; Y. L Lee; S. B Lee; S. J Lee; S. K Nam; J. K Oh; M. K Park; W. J Park; J. T Rhee; M. S Ryu; H. H. Shim; K. S Sim; J. K Woo

2003-01-01

441

Tissue chamber model of acute inflammation in farm animal species  

Microsoft Academic Search

A tissue chamber model of acute inflammation for use in comparative studies in calves, sheep, goats and pigs has been established and validated. Tissue chambers were prepared from silicon rubber tubing, of inner diameter 12.7mm, length 115mm and volume 15ml, with 10 holes, each of 6mm diameter, at each end. In each animal two or four chambers were inserted at

P Sidhu; F Shojaee Aliabadi; M Andrews; P Lees

2003-01-01

442

8. SEDIMENTATION CHAMBER, VIEW UPSTREAM (PLANK COVER REMOVED FOR CLARITY). ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. SEDIMENTATION CHAMBER, VIEW UPSTREAM (PLANK COVER REMOVED FOR CLARITY). BOX FLUME DROPS SLIGHTLY INTO CHAMBER ON LEFT SIDE. CHAMBER IS A SERIES OF BAFFLES DESIGNED TO SLOW THE FLOW OF WATER. FLOW IS REDUCED TO ALLOW PARTICULATES TO SETTLE TO THE BOTTOM. TWO SCREENS (NOT SHOWN) FILTER LARGER DEBRIS. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

443

A new combustion chamber for fast-burn applications  

Microsoft Academic Search

A new combustion chamber design is proposed in which it is possible to control the scale and intensity of turbulence generated just prior to ignition. A single cylinder engine has been fitted with the new chamber, and measurements of the turbulence field with a hot-wire anemometer are presented. The chamber design has been compared to a conventional bowl-in-piston design under

R. L. Evans; C. Cameron

1986-01-01

444

Radon progeny deposition in track-detection diffusion chambers  

Microsoft Academic Search

The sensitivity dependence for cylindrical diffusion chambers that are used for radon track-detection measurements on the deposition fraction of radon progeny atoms has been theoretically studied (sensitivity is the ratio: area track density\\/integrated 222Rn activity concentration). Experimentally, the sensitivity values of both the metal- and plastic-made chambers were determined. Results indicate that the experimental sensitivity for metal chambers is in

D. Pressyanov; I. Rusinov; G. Simeonov

1999-01-01

445

Double anterior chamber in a patient with glaucoma and microspherophakia  

PubMed Central

We report the case of a 16-year-old woman with microspherophakia and secondary open angle glaucoma. The patient presented with a membrane dividing the anterior chamber into two segments without edema or Descemet's membrane detachment. Slit lamp biomicroscopy, Pentacam, and specular microscopy images were obtained. Double anterior chamber is primarily found in patients with anterior chamber anomalies when there is no history of surgery or trauma.

Khakshoor, Hamid; Ansari-Astaneh, Mohammad-Reza; Shoeib, Mousa; Schliesser, Joshua A; Moshirfar, Majid

2011-01-01

446

Community Facilities, Jackson County.  

National Technical Information Service (NTIS)

The Community Facilities Plan is designed to provide an analysis of the existing facilities , and proposed recommended changes. Specific elements included are: Administration, Public Safety, Public Utilities, Public Works, Educational Facilities, and Recr...

J. D. McAlister

1971-01-01

447

Research on the Ignition-Chamber GDI Engine Combustion System  

NASA Astrophysics Data System (ADS)

The ignition-chamber GDI engine combustion system and its fuel injection strategy were presented and studied by multi-dimensional fluid dynamic (CFD) code and experiment. The CFD research result shows that the ignition-chamber combustion system and its fuel injection strategy can ensure that there is flammable mixture with appropriate concentration distribution near the spark plug to enhance the ignition reliability. The performance of the GDI engine with the ignition-chamber combustion system was investigated basing on the existing experiment condition. The result shows that the ignition-chamber combustion system has the potential of decreasing emissions and enhancing the combustion speed and stability.

Fu, Lei; Ishima, Tsuneaki; Long, Wu-Qiang; Tian, Jiang-Ping

448

Repair of isolated double-chambered right ventricle.  

PubMed

The finding of a double-chambered right ventricle (DCRV) is exceptionally rare as an isolated anomaly. It is a congenital cardiac anomaly in which the right ventricle is separated into two chambers, a proximal high-pressure chamber and a distal low-pressure chamber, by anomalous muscles or fibrous tissues in the right ventricular cavity. We report the case of a 6-year-old infant who was admitted for growth retardation. The patient was diagnosed with an isolated DCRV without any other associated congenital anomalies. The patient underwent a successful cardiac surgical procedure of enlargement repair; he was discharged in good clinical condition with a normal cardiac function. PMID:23860078

El Kouache, M; Babakhoya, A; Labib, S; El Madi, A; Atmani, S; Harandou, M; Abouabdilah, Y; Hida, M

449

Explosive Containment Chamber Vulnerability to Chemical Munition Fragment Impact  

SciTech Connect

Scenarios in which the explosive burster charge in a chemical munition accidentally detonates inside demilitarization containment chambers are analyzed. The vulnerability of an inner Auxiliary Pressure Vessel and the primary Explosive Containment Chamber to impact by fragments from the largest explosive charge expected to be placed in these chambers (M426, 8 inch, chemical, 7 lbs Comp B) is evaluated. Numerical (CTH) and empirical (ConWep) codes are used to characterize the munition fragments, and assess the consequences of their impact and penetration on the walls of these vessels. Both pristine and corroded configurations of the munition have been considered, with and without liquid agent fill. When the munition burster charge detonates, munition case fragments impact and perforate the Auxiliary Pressure Vessel wall, resulting in extensive breakup of this inner chamber and the formation of additional fragments. These residual munition case and Auxiliary Pressure Vessel fragments have sufficient mass and velocity to crater the Explosive Containment Chamber inner wall layer, with accompanying localized permanent deformation (bulging) of both the inner and outer chamber walls. The integrity of the Explosive Containment Chamber was retained under all of the APV / munition configurations considered in this study, with no evidence that primary (munition) or secondary (munition and Auxiliary Pressure Vessel) fragments will perforate the inner chamber wall. Limited analyses of munition detonation without the Auxiliary Pressure Vessel present indicate that some munition span fragments could form under those conditions that have sufficient mass and velocity to perforate the inner wall of the Explosive Containment Chamber.

Benham, R.A.; Fischer, S.H.; Kipp, M.E.; Martinez, R.R.

1999-02-01

450

EFFECTS OF ACTIVATED CHARCOAL FILTRATION AND OZONATION ON HYDROCARBON AND CARBONYL LEVELS OF AMBIENT AIR USED IN CONTROLLED-EXPOSURE CHAMBER STUDIES OF AIR POLLUTANT HUMAN HEALTH EFFECTS  

EPA Science Inventory

Air sampling experiments were done in 1985, 1987, and 1993 at the human-exposure chamber facility of the U.S. EPA Health Effects Research Laboratory in Chapel Hill, NC. easurements of VOC's by GC-FID and aldehyde measurements by the DNPH silica gel cartridge method were made, com...

451

Repetition rate target and fusion chamber systems for HiPER  

NASA Astrophysics Data System (ADS)

We review development in the repetition-rate target area systems and technologies within the Work Package 15 of the HiPER Preparatory Phase project. The activities carried out in 2009-2010 have been involving analysis of solutions and baseline design of major elements of the repetition-rated fusion chamber, analysis of prospective injector technologies, numerical modelling of target survival during acceleration phase and during flight in the environment of fusion chamber, analysis of options of remote handling, systems of mitigation of fusion debris, and others. The suggested solutions assume operation at the repetition rate of 10 Hz and fusion yield between 20 and 100 MJ. Shock ignition is assumed as the baseline ignition scenario, although some technologies are applicable in the fast ignition; a number of the technologies identified are exploitable as well in the indirect drive. The operation of the HiPER repetition-rate chamber will contribute to technology development for the Demonstration Reactor HiPER facility.

Rus, Bedrich; Edwards, Chris; Tyldesley, Mike; Griffiths, Mike; Le Garrec, Bruno; Perlado, Manolo; Perin, Jean-Paul; Guillaume, Didier; Neely, David; Polan, Ji?í; Kozlová, Michaela; Homer, Pavel; Nejdl, Jaroslav; Sanders, Steve; Havlík, Petr; Kopecký, Martin; Kola?ík, Vladimír; Papírek, Tomáš; Hlavá?, Martin; Haley, Richard; Macfarlane, Lewis; Alexander, Neil

2011-05-01

452

Experimental Analysis of Gaseous Chambers for the ATLAS Muon sub-detector Upgrade R&D  

NASA Astrophysics Data System (ADS)

CERN, the world's largest particle accelerator facility, has begun its ambitious Large Hadron Collider (LHC) program which is and will remain as the world energy frontier until at least 2030. ATLAS, one of the LHC experiments designed to search for new physics, has been taking data for two years. ATLAS has been investigating the necessary changes to its sub-detectors to withstand much higher instantaneous luminosity and to operate after 3000 fb-1 of integrated data. The goal is to achieve the same or better performance (spatial resolution, etc.) despite the large increase in event rate and final integrated dose. The current ATLAS Muon sub-detector will not be able to handle the increased luminosity of a factor of ten. This makes it necessary to replace the current muon sub-detector by possible new gaseous chambers that push their performance to limits never tested before. This talk will focus on the different lab experiments performed at CERN during the summers of 2011 and 2012, including functional uniformity results of a new ``T-series'' chamber design developed by the ATLAS Muon detector upgrade R&D team. As a result, a new visual mapping design was developed by the author that enabled an easier way to find anomalies in the chambers. This work has been presented to ATLAS Weekly Micromegas Meeting's 6 times during the summers of 2011 and 2012.

Angulo, Emmanuel

2012-11-01

453

Design and evaluation of an aeroacoustic wind tunnel for measurement of axial flow fans.  

PubMed

An anechoic wind tunnel dedicated to fan self-noise studies has been designed and constructed at the von Karman Institute The multi-chamber, mass flow driven design allows for all fan performance characteristics, aerodynamic quantities (e.g., wake turbulence measurements), and acoustic properties to be assessed in the same facility with the same conditions. The acoustic chamber performance is assessed using the optimum reference method and found to be within the ISO 3745 standards down to 150 Hz for pure tone and broadband source mechanisms. The additional influence of installation effects of an aerodynamic inlet was found to create a scattered sound field only near the source location, while still providing good anechoic results at more distant sound pressure measurement positions. It was found to have inflow properties, span-wise uniformity, and low turbulence intensity, consistent with those desired for fan self-noise studies. PMID:22225036

Bilka, M; Anthoine, J; Schram, C

2011-12-01

454

Technical Review of the Laboratory Biosphere Closed Ecological System Facility  

NASA Astrophysics Data System (ADS)

The "Laboratory Biosphere", a new closed ecological system facility in Santa Fe, New Mexico (USA) has been constructed and became operational in May 2002. Built and operated by the Global Ecotechnics consortium (Biosphere Technologies and Biosphere Foundation with Biospheric Design Inc., and the Institute of Ecotechnics), the research apparatus for intensive crop growth, biogeochemical cycle dynamics and recycling of inedible crop biomass comprises a sealed cylindrical steel chamber and attached variable volume chamber (lung) to prevent pressures caused by the expansion and contraction of the contained air. The cylindrical growing chamber is 3.7m (12 feet) long and 3.7m (12 foot) diameter, giving an internal volume of 34 m3 (1200 ft 3 ). The two crop growth beds cover 5.5 m2, with a soil depth of 0.3m (12 inches), with 12 x 1000 watt high-pressure sodium lights capable of variable lighting of 40-70 mol per m2 per day. A small soil bed reactor in the chamber can be activated to help with metabolism of chamber trace gases. The volume of the attached variable volume chamber (lung) can range between 0-11 m3 (0-400 ft 3 ). Evapotranspired and soil leachate water are collected, combined and recycled to water the planting beds. Sampling ports enable testing of water quality of leachate, condensate and irrigation water. Visual inspection windows provide views of the entire interior and growing beds. The chamber is also outfitted with an airlock to minimize air exchange when people enter and work in the chamber. Continuous sensors include atmospheric CO2 and oxygen, temperature, humidity, soil moisture, light level and water levels in reservoirs. Both "sniffer" (air ports) and "sipper" (water ports) will enable collection of water or air samples for detailed analysis. This paper reports on the development of this new soil-based bioregenerative life support closed system apparatus and its technical challenges and capabilities.

Dempster, W.; van Thillo, M.; Alling, A.; Allen, J.; Silverstone, S.; Nelson, M.

455

Chamber and target technology development for inertial fusion energy  

Microsoft Academic Search

Fusion chambers and high pulse-rate target systems for inertial fusion energy (IFE) must: regenerate chamber conditions suitable for target injection, laser propagation, and ignition at rates of 5 to 10 Hz; extract fusion energy at temperatures high enough for efficient conversion to electricity; breed tritium and fuel targets with minimum tritium inventory; manufacture targets at low cost; inject those targets

M Abdou; G Besenbruch; J Duke; L Forman; D Goodin; K Gulec; J Hoffer; H Khater; G Kulcinsky; J F Latkowski; B G Logan; B Margevicious; W R Meier; R W Moir; N Morley; A Nobile; S Payne; P F Peterson; R Peterson; R Petzoldt; K Schultz; W Steckle; L Sviatoslavsky; M Tillack; A Ying

1999-01-01

456

Measurement of plant water status by the pressure chamber technique  

Microsoft Academic Search

The pressure chamber has been widely used in the measurement of total water potential and pressure-volume relations of leaves, twigs and, to a lesser extent, roots. Some of the benefits and precautions in its use in these studies are reviewed and discussed. The pressure chamber has also been used to determine hydraulic resistances of plants, to collect xylem sap, to

Neil C. Turner

1988-01-01

457

MEASUREMENT OF ORGANIC COMPOUND EMISSIONS USING SMALL TEST CHAMBERS  

EPA Science Inventory

Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The follow...

458

Episodic magma chambers and amagmatic extension in the Josephine ophiolite  

Microsoft Academic Search

Geochemical and structural aspects of the Josephine ophiolite indicate that it formed by alternating cycles of magmatic and structural (amagmatic) extension. Episodic magma chambers are indicated by the presence of very primitive lavas in the lower pillow lavas which would have mixed into a magma chamber. Fe-Ti basalts that occur in the uppermost extrusive rocks and plagiogranites that occur along

Gregory D. Harper

1988-01-01

459

Intensive Irradiation Study on Monitored Drift Tubes Chambers  

Microsoft Academic Search

Monitored drift tube chambers (MDT) are the precision tracking detectors in the muon spectrometer of the ATLAS detector at the Large Hadron Collider (LHC). From simulations of the LHC operating conditions, the count rate in the inner barrel chamber of the muon spectrometer is expected to reach 500 Hz\\/cm2 and can be ten times higher in the luminosity upgrade under

P. Branchini; S. Di Luise; E. Graziani; C. Mazzotta; E. Meoni; G. Morello; A. Passeri; F. Petrucci; A. Policicchio; D. Salvatore; M. Schioppa

2007-01-01

460

Intensive irradiation study on Monitored Drift Tubes chambers  

Microsoft Academic Search

Monitored drift tube chambers (MDT) are the precision tracking detectors in the muon spectrometer of the ATLAS detector at the Large Hadron Collider (LHC). From simulations of the LHC operating conditions, the count rate in the inner barrel chamber of the muon spectrometers is expected to reach 500 Hz\\/cm2 and can be ten times higher in the luminosity upgrade under

P. Branchini; S. Di Luise; E. Graziani; C. Mazzotta; E. Meoni; G. Morello; A. Passeri; F. Petrucci; A. Policicchio; D. Salvatore; M. Schioppa

2006-01-01

461

ON THE USE OF THIMBLE CHAMBERS IN PHANTOMS  

Microsoft Academic Search

The results are given of investigations on the validity of the ; assumption that the thimble chamber will record faithfully (within 5%) the ; exposure dose delivered at the position of the center of a chamber. The ; Victoreen condenscr rmeter was examined over a wide range of quality and other ; physical factors. A detailed discussion is given on

1962-01-01

462

Identification of cosmic rays using drift chamber hit timing  

NASA Astrophysics Data System (ADS)

The CDFII detector at Fermilab contains a large drift chamber called the Central Outer Tracker (COT) which is used for measuring the trajectories of charged particles. We describe a method of identifying COT tracks as cosmic rays by using the drift chamber as a distributed time-of-flight detector.

Kotwal, Ashutosh V.; Gerberich, Heather K.; Hays, Christopher

2003-06-01

463

Thermoelectric Cloud Chamber showing Cosmic Ray and Natural Radioactivity Tracks  

NASA Astrophysics Data System (ADS)

Cosmic rays can be continuously observed in this thermoelectrically cooled diffusion cloud chamber. Greater track density is observed using radioactive sources. Ice water is used to cool the Peltier device (about 1 kg of ice per hour). Good tracks are observed within half an hour after the cloud chamber is turned on.

Rowland, S. Clark; Lee, B. E.

2007-05-01

464

Thermoelectric Cloud Chamber Showing Charged Subatomic Particle Tracks  

NASA Astrophysics Data System (ADS)

Alpha particle tracks can be photographed and their lengths measured in an introductory laboratory using this thermoelectrically cooled diffusion cloud chamber. Without a radioactive source, cosmic ray tracks can be observed. Ice water is used to cool the Peltier device (about 1 kg of ice per hour). Good tracks are observed within half an hour after the cloud chamber is turned on.

Rowland, S. Clark; Lee, B. E.

2007-05-01

465

Study of Factors Affecting Reactions in Environmental Chambers.  

National Technical Information Service (NTIS)

An experimental study has been conducted of effects of materials, spectrum, surface/volume ratio (S/V) and cleaning technique on the photochemical reactions observed in a smog chamber. A unique chamber and lighting system was used, which permitted indepen...

R. J. Jaffe

1975-01-01

466

Study of Factors Affecting Reactions in Environmental Chambers.  

National Technical Information Service (NTIS)

An experimental study has been conducted of effects of materials, spectrum, surface/volume ratio (S/V) and cleaning technique on the photochemical reactions observed in a smog chamber. A unique chamber and lighting system was used, which permitted indepen...

R. J. Jaffe F. C. Smith K. W. Last

1974-01-01

467

Growth of Mycobacterium lepraemurium in Cell-Impermeable Diffusion Chambers  

PubMed Central

Successful growth of Mycobacterium lepraemurium has been achieved by use of a specialized diffusion chamber technique. The cell-impermeable porous chambers were maintained in animals for periods up to 50 days with and without macrophages and LM cells. A generation time of 6 to 8 days was found for the acid-fast bacilli in chambers containing macrophages when maintained in the mouse. Also, cell-free chambers maintained in the mouse gave a generation time of 11 days for M. lepraemurium. There was no doubt that chambers maintained in a susceptible host provided greater yields of bacilli than chambers maintained in a nonsusceptible host such as the guinea pig. In fact, better yields were obtained when the chambers were maintained in monolayer petri plate cultures of mouse peritoneal macrophages than when held in the guinea pig. The most pertinent observation was that living cells are not essential for growth of M. lepraemurium, and the results suggest that multiplication can occur in a cell-free environment within a susceptible host. These studies give evidence that the use of porous chambers has promising possibilities for further investigations on the cultivation of other fastidious mycobacteria.

Rightsel, Wilton A.; Wiygul, William C.

1971-01-01

468

FEM Approximation of Internal Combustion Chambers for Knock Investigations  

Microsoft Academic Search

The resonances of SI engine combustion chambers are slightly excited during normal combustion but strongly excited by knock. In order to avoid knocking combustions extensive knowledge about knock and its effects is necessary. In this paper the combustion chamber of a serial production engine is modeled by finite elements. Modal analyses are performed in order to gain information about the

Sönke Carstens-Behrens; Mark Urlaub; Johann F. Böhme; Jürgen Förster; Franz Raichle; Robert Bosch

469

Factors Controlling the Structures of Magma Chambers in Basaltic Volcanoes.  

National Technical Information Service (NTIS)

The depths, vertical extents, and lateral extents of magma chambers and their formation are discussed. The depth to the center of a magma chamber is most probably determined by the density structure of the lithosphere; this process is explained. It is com...

L. Wilson J. W. Head

1991-01-01

470

EFFECTS OF OPEN-TOP CHAMBERS ON 'VALENCIA' ORANGE TREES  

EPA Science Inventory

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. ong-term ozone average concen...

471

7. SEDIMENTATION CHAMBER AT 520', CONSTRUCTED 19371938, VIEWED FROM DOWNSTREAM. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. SEDIMENTATION CHAMBER AT 520', CONSTRUCTED 1937-1938, VIEWED FROM DOWNSTREAM. DEBRIS REMOVED FROM TOP PLANKS FOR CLARITY. ONE OF TWO SPILLWAYS SEEN AT RIGHT. FLUSH VALVE SEEN AT LOWER LEFT AND WRENCH FOR VALVES IS PROPPED AGAINST CHAMBER. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

472

Performance of the CMS cathode strip chambers with cosmic rays  

Microsoft Academic Search

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47

S. Chatrchyan; V. Khachatryan; A. M. Sirunyan; W. Adam; B. Arnold; H. Bergauer; T. Bergauer; M. Dragicevic; M. Eichberger; J. Ero; M. Friedl; R. Fruhwirth; V. M. Ghete; J. Hammer; S. Hansel; M. Hoch; N. Hormann; J. Hrubec; M. Jeitler; G. Kasieczka; K. Kastner; M. Krammer; D. Liko; I. M. de Abril; I. Mikulec; F. Mittermayr; B. Neuherz; M. Oberegger; M. Padrta; M. Pernicka; H. Rohringer; S. Schmid; R. Schofbeck; T. Schreiner; R. Stark; H. Steininger; J. Strauss; A. Taurok; F. Teischinger; T. Themel; D. Uhl; P. Wagner; W. Waltenberger; G. Walzel; E. Widl; C. E. Wulz; V. Chekhovsky; O. Dvornikov; I. Emeliantchik; A. Litomin; V. Makarenko; I. Marfin; V. Mossolov; N. Shumeiko; A. Solin; R. Stefanovitch; J. S. Gonzalez; A. Tikhonov; A. Fedorov; A. Karneyeu; M. Korzhik; V. Panov; R. Zuyeuski; P. Kuchinsky; W. Beaumont; L. Benucci; M. Cardaci; E. A. De Wolf; E. Delmeire; D. Druzhkin; M. Hashemi; X. Janssen; T. Maes; L. Mucibello; S. Ochesanu; R. Rougny; M. Selvaggi; H. Van Haevermaet; P. Van Mechelen; V. Adler; S. Beauceron; S. Blyweert; J. DHondt; S. De Weirdt; O. Devroede; J. Heyninck; A. Kalogeropoulos; J. Maes; M. Maes; M. U. Mozer; S. Tavernier; W. Van Doninck; P. Van Mulders; I. Villella; O. Bouhali; E. C. Chabert; O. Charaf; B. Clerbaux; G. De Lentdecker; V. Dero; S. Elgammal; A. P. R. Gay; G. H. Hammad; P. E. Marage; S. Rugovac; C. V. Velde; P. Vanlaer; J. Wickens; M. Grunewald; B. Klein; A. Marinov; D. Ryckbosch; F. Thyssen; M. Tytgat; L. Vanelderen; P. Verwilligen; S. Basegmez; G. Bruno; J. Caudron; C. Delaere; P. Demin; D. Favart; A. Giammanco; G. Gregoire; V. Lemaitre; O. Militaru; S. Ovyn; K. Piotrzkowski; L. Quertenmont; N. Schul; N. Beliy; E. Daubie; G. A. Alves; M. E. Pol; M. H. G. Souza; W. Carvalho; D. D. Damiao; C. D. Martins; S. F. De Souza; L. Mundim; V. Oguri; A. Santoro; S. M. S. Do Amaral; A. Sznajder; Trfp Tomei; M. A. F. Dias; E. M. Gregores; S. F. Novaes; K. Abadjiev; T. Anguelov; J. Damgov; N. Darmenov; L. Dimitrov; V. Genchev; P. Iaydjiev; S. Piperov; S. Stoykova; G. Sultanov; R. Trayanov; I. Vankov; A. Dimitrov; M. Dyulendarova; V. Kozhuharov; L. Litov; E. Marinova; M. Mateev; B. Pavlov; P. Petkov; Z. Toteva; G. M. Chen; H. S. Chen; W. Guan; C. H. Jiang; D. Liang; B. Liu; X. Meng; J. Tao; J. Wang; Z. Wang; Z. Xue; Z. Zhang; Y. Ban; J. Cai; Y. Ge; S. Guo; Z. Hu; Y. Mao; S. J. Qian; H. Teng; B. Zhu; C. Avila; M. B. Ruiz; C. A. C. Montoya; A. Gomez; B. G. Moreno; A. A. O. Rios; A. F. O. Oliveros; D. R. Romero; J. C. Sanabria; N. Godinovic; K. Lelas; R. Plestina; D. Polic; I. Puljak; Z. Antunovic; M. Dzelalija; V. Brigljevic; S. Duric; K. Kadija; S. Morovic; R. Fereos; M. Galanti; J. Mousa; A. Papadakis; F. Ptochos; P. A. Razis; D. Tsiakkouri; Z. Zinonos; A. Hektor; M. Kadastik; K. Kannike; M. Muntel; M. Raidal; L. Rebane; E. Anttila; S. Czellar; J. Harkonen; A. Heikkinen; V. Karimaki; R. Kinnunen; J. Klem; M. J. Kortelainen; T. Lampen; K. Lassila-Perini; S. Lehti; T. Linden; P. Luukka; T. Maenpaa; J. Nysten; E. Tuominen; J. Tuominiemi; D. Ungaro; L. Wendland; K. Banzuzi; A. Korpela; T. Tuuva; P. Nedelec; D. Sillou; M. Besancon; R. Chipaux; M. Dejardin; D. Denegri; J. Descamps; B. Fabbro; J. L. Faure; F. Ferri; S. Ganjour; F. X. Gentit; A. Givernaud; P. Gras; G. H. de Monchenault; P. Jarry; M. C. Lemaire; E. Locci; J. Malcles; M. Marionneau; L. Millischer; J. Rander; A. Rosowsky; D. Rousseau; M. Titov; P. Verrecchia; S. Baffioni; L. Bianchini; M. Bluj; P. Busson; C. Charlot; L. Dobrzynski; R. G. de Cassagnac; M. Haguenauer; P. Mine; P. Paganini; Y. Sirois; C. Thiebaux; A. Zabi; J. L. Agram; A. Besson; D. Bloch; D. Bodin; J. M. Brom; E. Conte; F. Drouhin; J. C. Fontaine; D. Gele; U. Goerlach; L. Gross; P. Juillot; A. C. Le Bihan; Y. Patois; J. Speck; P. Van Hove; C. Baty; M. Bedjidian; J. Blaha; G. Boudoul; H. Brun; N. Chanon; R. Chierici; D. Contardo; P. Depasse; T. Dupasquier; H. El Mamouni; F. Fassi; J. Fay; S. Gascon; B. Ille; T. Kurca; T. Le Grand; M. Lethuillier; N. Lumb; L. Mirabito; S. Perries; M. V. Donckt; P. Verdier; N. Djaoshvili; N. Roinishvili; V. Roinishvili; N. Amaglobeli; R. Adolphi; G. Anagnostou; R. Brauer; W. Braunschweig; M. Edelhoff; H. Esser; L. Feld; W. Karpinski; A. Khomich; K. Klein; N. Mohr; A. Ostaptchouk; D. Pandoulas; G. Pierschel; F. Raupach; S. Schael; A. S. von Dratzig; G. Schwering; D. Sprenger; M. Thomas; M. Weber; B. Wittmer; M. Wlochal; O. Actis; G. Altenhofer; W. Bender; P. Biallass; M. Erdmann; G. Fetchenhauer; J. Frangenheim; T. Hebbeker; G. Hilgers; A. Hinzmann; K. Hoepfner; C. Hof; M. Kirsch; T. Klimkovich; P. Kreuzer; D. Lanske; M. Merschmeyer; A. Meyer; B. Philipps; H. Pieta; H. Reithler; S. A. Schmitz; L. Sonnenschein; M. Sowa; J. Steggemann; H. Szczesny; D. Teyssier; C. Zeidler; M. Bontenackels; M. Davids; M. Duda; G. Flugge; H. Geenen; M. Giffels; W. H. Ahmad; T. Hermanns; D. Heydhausen; S. Kalinin; T. Kress; A. Linn

2010-01-01

473

512X512 mm Two-Coordinate Proportional Chamber.  

National Technical Information Service (NTIS)

Description and performances of a two-coordinate module of proportional chambers of 512x512 mm are presented. The pitch of signal wires is 2 mm. The chambers have high uniformity of performances in area; supporting wires are not used. The detectors are in...

V. N. Afonas'ev V. P. Chernyshev V. D. Peshekhonov

1979-01-01

474

Performance of a pencil ionization chamber in various radiation beams  

Microsoft Academic Search

Pencil ionization chambers were recommended for use exclusively in the computed tomography (CT) dosimetry, and, from the start, they were developed only with this application in view. In this work, we studied the behavior of a pencil ionization chamber in various radiation beams with the objective of extending its application. Stability tests were performed, and calibration coefficients were obtained for

Ana F. Maia; Linda V. E. Caldas

2003-01-01

475

Calibration of ionization chambers in air kerma length  

Microsoft Academic Search

Pencil ionization chambers are employed for the direct determination of the computed tomography dose index (CTDI), which is used for patient dosimetry in CT examinations. The chambers are calibrated in air kerma length in a reference x-ray field. The precision of calibration is influenced by several factors which are investigated in the present work. It is shown that the best

François O. Bochud; Mihail Grecescu; Jean-François Valley

2001-01-01

476

THE LIQUID HYDROGEN BUBBLE CHAMBER CBH81: PROTECTION AND SAFETY  

Microsoft Academic Search

In the operation of a liquid hydrogen bubble chamber, danger to ; personnel and to the apparatus from the utilization of gas liquified at low ; temperature and from the utilization of hydrogen at the same time as explosive ; gas must be guarded against. The precautions and monitoring in the area of ; chamber protection, vacuum surveillance, and prevention

Penet

1961-01-01

477

Reporting central tendencies of chamber measured surface emission and oxidation  

Microsoft Academic Search

Methane emissions, concentrations, and oxidation were measured on eleven MSW landfills in eleven states spanning from California to Pennsylvania during the three year study. The flux measurements were performed using a static chamber technique. Initial concentration samples were collected immediately after placement of the flux chamber. Oxidation of the emitted methane was evaluated using stable isotope techniques. When reporting overall

Tarek Abichou; Jeremy Clark; Jeffery Chanton

2011-01-01

478

THE CARBON DIOXIDE LEAKAGE FROM CHAMBERS MEASURED USING SULFUR HEXAFLUORIDE  

EPA Science Inventory

In plant chamber studies, if Co2 leaking from a chamber is not quantified, it can lead to an overestimate of assimilation rates and an underestimate of respiration rates: consequently, it is critical that Co2 leakage be determined. Sulfur Hexafluoride (SF6) was introduced into t...

479

30 CFR 57.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2013 CFR

...Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be flushed with a suitable solvent after the stem is pulled...

2013-07-01

480

Automated Monitoring of Soil Respiration: A Moving Chamber Design  

Microsoft Academic Search

measurements to predict the long-term dynamics of soil C pools will remain deficient. The importance of quanti- We designed, constructed, and tested an automated chamber sys- fying rates of CO2 efflux from soils was recently accentu- tem for continuously monitoring soil respiration. Our objective was to design a chamber that would permit monitoring of CO2 efflux ated by the European

Nelson T. Edwards; Jeffery S. Riggs

481

Study on Parameters of Fast Ionization Chambers with Different Gases.  

National Technical Information Service (NTIS)

Optimum parameters of a fast ionization chamber have been selected with the aim of using it in measuring cross sections of fission of a number of isotopes. The main chamber characteristics have been investigated, such as N ionization value, I amplitude an...

A. K. Gordyushin N. N. Semenova

1978-01-01

482

Operational data on the liquid phase tar chamber at Leuna  

Microsoft Academic Search

This file is a series of operational records and diagrams of the liquid phase tar chamber at Leuna. According to Haehnel (in a brief general section) in the chamber a brown coal low temperature carbonization tar was distilled with a small amount of oil. Lighter fractions were led off and the residue was cycled to the liquid phase hydrogenation. When

2008-01-01

483

Dynamic chamber armor behavior in IFE and MFE  

Microsoft Academic Search

The chamber wall armor is subject to demanding conditions in both inertial fusion energy (IFE) and magnetic fusion energy (MFE) chambers. This paper assesses the requirements on armor imposed by the operating conditions in IFE and MFE, including energy deposition density, time of deposition and frequencies, and discusses their impact on the performance of the candidate armor materials.

A. R. Raffray; G. Federici; A. Hassanein; D. Haynes

2002-01-01

484

Performance Evaluation of Portable Refuge Shelters/Chambers.  

National Technical Information Service (NTIS)

This protocol addresses the performance evaluation of mine refuge chambers for use in underground coal mines during a mine disaster. The evaluations will include injecting CO2 and heat and humidity into the chamber while removing O2 (and air) in order to ...

2007-01-01

485

Flow measurements in a model ramjet secondary combustion chamber  

Microsoft Academic Search

Experimental studies were conducted on a typical secondary combustion chamber of a ramjet to understand the influence of various inlet parameters such as primary nozzle configuration, secondary air injection angle, and flow Reynolds numbers on the secondary combustion chamber (SCC) performance. Cold flow studies were made with air as the flow medium for both primary and secondary jets followed by

Lazar T. Chittilapilly; S. Venkateswaran; P. J. Paul; H. S. Mukunda

1990-01-01

486

Study of convective heat transfer in gas turbine combustion chambers  

Microsoft Academic Search

A detailed investigation of the effect of swirler angle, stabilizing angle and flow rate upon the flow pattern, intensity of turbulence and heat transfer in cold combustion chambers is presented. The results indicate that a central recirculation flow is formed upstream in case of small swirl and along the whole chamber in case of high swirl. This recirculation is shown

M. M. Elkotb; M. M. Hilal; J. A. J. Wahham

1982-01-01

487

Prediction of temperature front in a gas turbine combustion chamber  

Microsoft Academic Search

Numerical computation has been applied to investigate the temperature field in a gas turbine combustion chamber. The simulation assumed that pressure imbalance conditions of air flow between primary and secondary inlets occur. The combustion chamber under study is part of a 70MW gas turbine from an operating combined cycle power plant. The combustion was simulated with normal fuel–air flow rate

F. Z. Sierra; J. Kubiak; G. González; G. Urquiza

2005-01-01

488

Gas and aerosol wall losses in Teflon film smog chambers  

Microsoft Academic Search

Large smog chambers (approx.60 m³) constructed of FEP Teflon film are frequently used to study photochemistry and aerosol formation in model chemical systems. In a previous paper a theory for aerosol wall loss rates in Teflon film smog chambers was developed; predicted particle loss rates were in good agreement with measured rates. In the present paper, measurements of wall deposition

Peter H. McMurry; Daniel Grosjean

1985-01-01

489

Sub-combustion chamber of an internal combustion engine  

Microsoft Academic Search

In a cylinder head in an internal combustion engine having a cylinder body to which the cylinder head is installed, with a gasket placed therebetween, the cylinder head is described including a pre-combustion chamber having a cylindrical portion for receiving a ceramic hot plug; and a ceramic hot plug disposed in the cylindrical portion of the pre-combustion chamber. The improvement

Toeda

1987-01-01

490

Structure of divided combustion chamber for diesel engine  

Microsoft Academic Search

A structure is described defining a divided combustion chamber of a diesel engine consisting of: an upper ceramic member having a substantially hemispherical head and a lower ceramic member having an injection port, the lower ceramic member meeting with the upper ceramic member at an interface to form the divided combustion chamber therein, the upper ceramic member including at least

T. Morita; Wakasa; Y. Ogawa; T. Ogasawara

1986-01-01

491

Effects of Open-Top Chambers on 'Valencia' Orange Trees.  

National Technical Information Service (NTIS)

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long...

D. M. Olszyk B. K. Takemoto G. Kats P. J. Dawson C. L. Morrison

1992-01-01

492

Sports Facility Management.  

ERIC Educational Resources Information Center

|The numbers of both sports facility management college courses and sport and exercise facilities are increasing, along with the need for an understanding of the trends and management concepts of these facilities. This book focuses exclusively on managing facilities where sporting events occur and includes examples in physical education,…

Walker, Marcia L., Ed.; Stotlar, David K., Ed.

493

Laser damage study on the first-wall LMJ target chamber  

NASA Astrophysics Data System (ADS)

Inertial fusion targets are of two basics types: direct drive and indirect drive. The french Laser MegaJoule (LMJ) will preferentially use indirect drive experiments. However, to contribute to the determination of the best target for inertial fusion energy, both direct and indirect drive will be considered on LMJ-facility. That is why studies on materials for use as first-wall LMJ target chamber and for different applications are of significant interest. In direct drive, targets will be directly heated and imploded by intense 351-nm wavelength laser light and part of this UV energy will be back-scattered off the target surface and consequently deposited onto the target chamber first wall. Such a deposited fluence should average 0.3-J/cm2. The aim of this study was to determine both the fluence level at which physical damage occurs on some considered protective materials and the associated damage mechanisms. Investigations have been carried out on boron carbide and carbon-based materials. Basically, experiments consisted of illuminating samples with a 355-nm gaussian pulse of roughly 3-ns duration generated by frequency conversion through KDP- crystals of a YAG-laser light. In our investigations, characterization of ejected species and transient hemispherical directional reflectivity measurement of the illuminated materials were conducted. All these experiments have shown that boron carbide was a better candidate than carbon-based materials as first-wall LMJ target chamber use. Analyzing the defect type, size and density and the composition and physical-state of the considered materials has allowed predicting the impact of induced-ablation of the first-wall on LMJ target chamber use and lifetime. Composition analysis were addressed using micro-Raman spectroscopy. Preliminary experiments have revealed significant changes in damage mechanism versus laser fluence.

Dubern, Christelle; Bruneel, J.-L.; Chadeyron, Patrick; Cordillot, C.; Couzi, M.; Fornier, Anne; Joubert, Pierre; Schirmann, Daniel

1999-04-01

494

Verifying Sensor Response to Difficult Chemicals with a New Test Chamber Concept  

SciTech Connect

In this article we discuss the application of technology innovations to optimize detection of hard-to-measure (less- or semi-volatile) compounds. These chemicals are found all around us: in pesticides and herbicides, the higher boiling polyaromatic hydrocarbons in diesel exhaust, and linked polyurethane foams in products ranging from hiking boots to acoustic ceilings. They appear in low concentrations and evaporate very slowly. These heavier chemicals are rarely measured accurately because they stick to surfaces and sampling equipment and, consequently, are not reliably sampled or delivered to analytical detectors. It’s like trying to identify cold, sticky honey by getting it to flow in through a sampling tube to a detector –it will hardly move. Honey generally coats out on surfaces and sample lines to the extent that even if it is detected, the amount present is vastly underestimated. Researchers at Pacific Northwest National Laboratory (PNNL) addressed the problem by developing a chamber facility with instrumentation that can overcome the under-reporting of these ubiquitous chemical compounds. The atmospheric chemistry chamber provides a controlled environment in which to certify the accuracy of and conditions under which sensors can best respond to volatile and semi-volatile chemicals. The facility is designed to handle and measure chemicals at the levels at which they are found in nature. Test environments can be created in which atmospheric concentrations are at low part-per-trillion concentrations. These concentrations are equivalent to an herbicide off-gassing from a commercially grown apple. The chamber can be set up to simulate releases ranging from industrial vents with high concentrations to releases from surfaces, soils, and/or vegetation where the concentrations are low.

Maughan, A. D.; Birnbaum, Jerome C.; Probasco, Kathleen M.

2004-06-01

495

The PHENIX Drift Chamber Front End Electroncs  

NASA Astrophysics Data System (ADS)

The PHENIX Drift Chamber (DC) is designed to operate in the high particle flux environment of the Relativistic Heavy Ion Collider and provide high resolution track measurements. It is segmented into 80 keystones with 160 readout channels each. The Front End Electronics (FEE) developed to meet the demanding operating conditions and the large number of readout channels of the DC will be discussed. It is based on two application specific integrated circuits: the ASD8 and the TMC-PHX1. The ASD8 chip contains 8 channels of bipolar amplifier-shaper-discriminator with 6 ns shaping time and ? 20 ns pulse width, which satisfies the two track resolution requirements. The TMC-PHX1 chip is a high-resolution multi-hit Time-to-Digital Converter. The outputs from the ASD8 are digitized in the Time Memory Cell (TMC) every (clock period)/32 or 0.78 ns (at 40 MHz), which gives the intrinsic time resolution of the system. A 256 words deep dual port memory keeps 6.4 ?s time history of data at 40 MHz clock. Each DC keystone is supplied with 4 ASD8/TMC boards and one FEM board, which performs the readout of the TMC-PHX1's, buffers and formats the data to be transmitted over the Glink. The slow speed control communication between the FEM and the system is carried out over ARCNET. The full readout chain and the data aquisition system are being tested.

Pancake, C.; Velkovska, J.; Pantuev, V.; Fong, D.; Hemmick, T.

1998-04-01

496

Chemistry of radiation damage to wire chambers  

SciTech Connect

Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF{sub 4}/iC{sub 4}H{sub 10} gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF{sub 4}-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF{sub 4}, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF{sub 4}/iC{sub 4}H{sub 10} gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C{sub 2}H{sub 6}. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl{sub 3}F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds.

Wise, J.

1992-08-01

497

OPERA Resistive Plate Chambers underground test results  

NASA Astrophysics Data System (ADS)

The OPERA experiment [M. Guler et al., CERN/SPSC 2000-028, SPSC/P318, LNGS P25/2000, July 10, 2000; M. Guler et al., CERN/SPSC 2001-025, SPSC/M668, LNGS-EXP 30/2001 Add. 1/01, August 21, 2001] will study ??? oscillations through ? appearance on the 732 Km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 44 layers of high resistivity bakelite Resistive Plate Chambers (RPCs) operated in streamer mode. Each layer covers about 70 m2. Four RPC planes were instrumented and the first tests were performed confirming a good behaviour of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality tests performed at surface. Counting rates are below 20 Hz/m2. Single an multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with expectations.

Bergnoli, A.; Brugnera, R.; Candela, A.; Carrara, E.; Ciesielski, R.; Dal Corso, F.; Degli Esposti, L.; di Giovanni, A.; D'Incecco, M.; di Troia, C.; Dusini, S.; Fanin, C.; Felici, G.; Gambarara, A.; Garfagnini, A.; Gatta, M.; Grianti, F.; Gustavino, C.; Lindozzi, M.; Longhin, A.; Mengucci, A.; Monacelli, P.; Paoloni, A.; Stanco, L.; Tatananni, E.; Terranova, F.; Spinetti, M.; Stipcevic, M.; Sugonyaev, V.; Terminiello, L.; Ventura, M.; Votano, L.

2006-08-01

498

A very large area Micro Pixel Chamber  

NASA Astrophysics Data System (ADS)

A Micro Pixel Chamber, called “?-PIC”, is a gaseous 2D imaging detector with a fine pixel electrode based on the Printed Circuit Board technology, and we developed it for the X/gamma-ray imaging and the tracking of the charged particles [A. Ochi, et al., Nucl. Instr. and Meth. A 478 (2002) 196; T. Nagayoshi, et al., Nucl. Instr. and Meth. A 525 (2004) 20.]. The previous ?-PIC has a fine position resolution, a high gas gain, a good gas gain uniformity and the stable operation. Although the detection area of the previous ?-PIC (˜10×10cm) is not large enough for a variety of the application, for example an MeV gamma-ray Compton camera [T. Tanimori, et al., New Astron. Rev. 48 (2004) 263.] and dark matter search [T. Tanimori, et al., Phys. Lett. B 578 (2004) 241.]. Therefore, we developed a new ?-PIC ha